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Transcript
USER’S MANUAL
Model DRC-93C
Temperature Controller
Obsolete Notice:
This manual describes an obsolete Lake Shore product. This manual is a copy from our archives
and may not exactly match your instrument. Lake Shore assumes no responsibility for this manual
matching your exact hardware revision or operational procedures. Lake Shore is not responsible
for any repairs made to the instrument based on information from this manual.
Lakeshore.
Lake Shore Cryotronics, Inc.
575 McCorkle Blvd.
Westerville, Ohio 43082-8888 USA
E-Mail Addresses:
[email protected]
[email protected]
Visit Our Website:
www. lakeshore.com
Fax: (614) 891-1392
Telephone: (614) 891-2243
Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake Shore Cryotronics, Inc.
No government or other contractual support or relationship whatsoever has existed which in any way affects or mitigates proprietary
rights of Lake Shore Cryotronics, Inc. in these developments. Methods and apparatus disclosed herein may be subject to U.S.Patents
existing or applied for. Lake Shore Cryotronics, Inc. reserves the right to add, improve, modify, or withdraw functions, design
modifications, or products at any time without notice. Lake Shore shall not be liable for errors contained herein or for incidental or
consequentialdamages in connection with furnishing, performance, or use of this material.
Obsolete Manual
March 1988
SERIAL NUMBER
MB SOFTWARE
DB SOFTWARE
I N S T RU C T I O N
M A N U A L
M O D E L
D R C - 9 3 C
T E M P E R A T U R E
C O N T R O L L E R
Input Card Configuration
Input A
9210-3
-6
Standard 3 volt Configuration
6 Volt Diode Configuration
9215-15
-150
Standard 15 Nanofarad Capacitance Input
150 Nanofarad Configuration
9220-3
Standard 3 volt Configuration
6 Volt Configuration
100 ohm platinum conversion module
1000 ohm platinum conversion module
27 ohm Rh-Fe conversion module
-6
-P2
-P3
-R1
9305
Thermocouple Input Card
9317C
Ultra-low (0.3K) Germanium input Card
9318C
Germanium/Carbon Glass Input Card
Input B
No Input Card
Precision Option ( s )
8223 RS-232C Interface
8225 Analog Output Interface (0-10 volt)
8229 Scanner Input Option
8001
8002
Output Power Option
W6 0
9126 High Resolution Set Point
This manual applies directly to instruments with Serial Number
17000 and higher.
COPYRIGHT 1988, Lake Shore Cryotronics, Inc.
Westerville, Ohio U.S.A.
WARRANTY
Lake Shore Cryotronics, Inc., the manufacturer, warrants this product to
the owner for a period of 12 months from the date of shipment. During the
warranty period, under authorized return of instruments or component
parts to Lake Shore freight prepaid, the company will repair, or at its
option replace, any part found to be defective in material or
workmanship, without charge to the Owner for parts, service labor or
associated customary shipping cost. Replacement or repaired parts will
be warranted for only the unexpired portion of the original warranty.
All products are thoroughly tested and calibrated to published
specifications prior to shipment. Calibration Certifications are offered
for six month periods only. Where such documentation must be updated, a
re-certification service is offered by Lake Shore Cryotronics, Inc. at a
reasonable cost.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from improper or
inadequate maintenance, unauthorized modification or misuse, operation
outside of the environmental specifications for any product or part or
buyer-supplied software or interfacing.
THIS WARRANTY IS IN LIEU OF ANY OTHER WARRANTIES, EXPRESSED OR IMPLIED,
INCLUDING MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, WHICH ARE
EXPRESSLY EXCLUDED. THE OWNER AGREES THAT LAKE SHORE'S LIABILITY WITH
RESPECT TO THIS PRODUCT SHALL BE SET FORTH IN THIS WARRANTY, AND
INCIDENTAL OR CONSEQUENTIAL DAMAGES ARE EXPRESSLY EXCLUDED.
CERTIFICATION
Lake Shore Cryotronics, Inc. certifies that this product has been
inspected and tested in accordance with its published specifications and
that this product met its published specifications at the time of
shipment.
The accuracy and calibration of this product at the time of shipment are
traceable to the United States National Bureau of Standards.
COPYRIGHT 3/88 LSCI
Model
SECTION I
-
T A B L E
O F
C O N T E N T S
DRC-93C Temperature Controller
GENERAL INFORMATION
........................
........................
.......................
.........................
1.1 INTRODUCTION
1.2
1.3
1.4
DESCRIPTION.
SPECIFICATIONS
OPTIONS..
1-1
1-1
1-3
1-3
SECTION II - INSTALLATION
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
........................
.....................
.....................
..................
.....................
................
......................
....................
...............
..............
..................
.....................
...........
INTRODUCTION
INITIAL INSPECTION
PREPARATION FOR USE
2.3.1
Power Requirements
2.3.2
PowerCord.
2.3.3
Grounding Requirements
2.3.4
BenchUse
2.3.5
RackMounting
2.3.6
Sensor Input Connections
2.3.7
J3 Sensor Output Monitors
2.3.8
SENSOR ID Switches
2.3.9
Heater Power
2.3.9.1
MAX HEATER POWER Limit
2.3.9.2
Current or Power Output Display
REMOTE SENSOR ID Connector
IEEE-488 INTERFACE Connector
OPTIONS..
ENVIRONMENTAL REQUIREMENTS
2.7.1
Operating Temperature
2.7.2
Humidity/Altitude
REPACKAGING FOR SHIPMENT
.......
.................
................
.........................
.................
................
.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
- OPERATING INSTRUCTIONS
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . .
INSTRUMENT CONFIGURATION . . . . . . . . . . . . . . . . . . .
3.2.1
Input Card Configurations . . . . . . . . . . . . . . .
Single Input Card . . . . . . . . . . . . . . . . . . .
3.2.2
3.2.3
Dual Input Cards . . . . . . . . . . . . . . . . . . . .
3.2.4
Old Version Input Cards . . . . . . . . . . . . . . . .
CURVE ENTRY.. . . . . . . . . . . . . . . . . . . . . . . . .
PRECISION OPTIONS . . . . . . . . . . . . . . . . . . . . . . .
3.4.1
The Model 8000 Precision Option . . . . . . . . . . . .
The Model 8001 Precision Option . . . . . . . . . . . .
3.4.2
2-1
2-1
2-1
2-1
2-1
2-1
2-2
2-2
2-2
2-3
2-3
2-4
2-4
2-4
2-4
2-5
2-5
2-5
2-5
2-5
2-5
SECTION III
3.1
3.2
3.3
3.4
3.4.3
The Model 8002-05 Precision option
COPYRIGHT 3/88 LSCI
...........
3-1
3-1
3-1
3-1
3-1
3-1
3-1
3-2
3-2
3-2
3-2
i
TABLE OF CONTENTS. CONT'D
3.5
3.6
.....................
CONTROLS AND INDICATORS . . . . . . . . . . . . . . . . . . . .
CONTROL FUNDAMENTALS
3-2
3-2
FRONT PANEL DESCRIPTION
3.7
3.8
...........................
...................
....................
....................
...................
TEMPERATURE BLOCK . . . . . . . . . . . . . . . . . . . . . . .
3.8.1
Sample and Control Sensor Inputs . . . . . . . . . . . .
3.8.2
Upper and Lower SENSOR Number . . . . . . . . . . . . .
3.8.3
8229 Scanner Input Option . . . . . . . . . . . . . . .
3.8.4
SCAN Function . . . . . . . . . . . . . . . . . . . . .
3.8.5
The SCAN Dwell Time . . . . . . . . . . . . . . . . . .
3.8.6
Upper and Lower Display Units . . . . . . . . . . . . .
POWERON
3.7.1
Power Up Sequence
3.7.2
Power-up Status
3.7.3
Blue Legend Keys
3.7.2
Black Legend Keys
.................
...............
3.8.6.2.1Voltage
Units . . . . . . . . . . . .
3.8.6.2.2
Resistance Units . . . . . . . . . .
Capacitance Units . . . . . . . . . .
3.8.6.2.3
Display Resolution . . . . . . . . . . . . . . . . . . .
3.8.6.1
3.8.6.2
3.8.7
ii
3-5
3-5
3-5
3-6
3-6
3-6
3-6
3-6
3-7
3-7
3-7
3-7
3-7
3-8
3-9
3-9
......
..............
.....................
SENSOR CURVE SELECTION . . . . . . . . . . . . . . . . . . . .
3-10
3.9.1
Standard and Precision Option Curves . . . . . . . . . . 3-10
3.9.1.1
The Precision Option . . . . . . . . . . . . . 3-10
3.9.1.2
Display of Accessed Curve Number . . . . . . . 3-10
Addition of 8229 Scanner Option . . . . . . . . 3-11
3.9.1.3
Changing the Curve used by a Sensor . . . . . . 3-11
3.9.1.4
3.9.2
External Scanners Models 8085 . . . . . . . . . . . . . 3-11
Selection of the REMOTE POSITION DATA . . . . . 3-11
3.9.2.1
The Correlation Table . . . . . . . . . . . . . 3-12
3.9.2.2
3.9.2.3
Modifying the Correlation Table from
the Front Panel . . . . . . . . . . . . . . . . 3-12
3.9.3
Programming Curves from the Front Panel . . . . . . . . 3-13
3.9.3.1
Accessing Stored Curve Data . . . . . . . . . . 3-13
3.9.3.2
Entering New Curves . . . . . . . . . . . . . . 3-14
3.9.3.3
Editing Existing Curve Data . . . . . . . . . . 3-15
3.9.3.4
Summary of Curve Programming from the
Front Panel . . . . . . . . . . . . . . . . . . 3-15
3.8.8
3.8.9
3.9
Units Select
Sensor Units Mode
3-2
3-2
3-3
3-3
3-5
3.8.7.1
Temperature Display Resolution Set
Filtering the A and B Inputs
Math Functions
COPYRIGHT 3/88 LSCI
TABLE OF CONTENTS, CONT'D
. . . . . . . . . . . . . . . . . . 3-16
........................
3-16
. . . . . . . . . . . . . . . . . . . . . . . . . . 3-16
.........................
3-16
.........................
3-17
. . . . . . . . . . . . . . . . . . 3-17
HEATER POWER . . . . . . . . . . . . . . . . . . . . . . . . .
3-17
3-17
3.11.1 HEATER % . . . . . . . . . . . . . . . . . . . . . . . .
3.11.2 The HEATER POWER RANGE . . . . . . . . . . . . . . . . . 3-17
LOCAL/REMOTEBLOCK . . . . . . . . . . . . . . . . . . . . . .
3-19
3-19
3.12.1 LOCAL . . . . . . . . . . . . . . . . . . . . . . . . .
3.12.2 REMOTE . . . . . . . . . . . . . . . . . . . . . . . . .
3-19
3.10 SET POINT AND CONTROL BLOCK
3.10.1 SETPOINT
3.11.2 GAIN
3.11.3 RATE.
3.11.4 RESET
3.11.5 MANUAL HEATER POWER
3.11
3.12
REAR PANEL DESCRIPTION
3.13 REMOTE SENSOR ID
.......................
3.14 HEATER CURRENT LIMIT
SECTION IV
-
.....................
3-19
3-19
REMOTE OPERATION
.....................
GENERAL IEEE SPECIFICATIONS AND OPERATION . . . . . . . . . .
INTERFACE CAPABILITIES . . . . . . . . . . . . . . . . . . .
DRC-93C IEEE-488 ADDRESS SWITCH . . . . . . . . . . . . . . .
4.4.1 Terminating Characters (delimiters) . . . . . . . . .
4.4.2 Talker and/or Listener Configuration . . . . . . . . .
4.4.3
The IEEE-488 INTERFACE bus address . . . . . . . . . .
4-3
4-3
4-3
4-5
IEEE-488 BUS COMMANDS
4.5.1 The Uniline Commands
4.5.2 The Universal Commands
4.5.3
The Addressed Commands
4.5.4
The Unaddress Commands
4.5.5
Device-Dependent Commands
4.5.6
Talker and Listener Status
4-5
4-5
4-5
4-5
4-6
4-6
4-6
4-1. IEEE-488 INTERFACE
4-1
4.2
4-1
4.3
4.4
4.5
4.6
4.7
. . . . ... .. .. .. .. .. ....... .. .. .. .. .. . .
...............
...............
...............
..............
..............
PROGRAMMING INSTRUCTIONS . . . . . . . . . . . . . . . . . .
4.6.1 Commands and Requests . . . . . . . . . . . . . . . .
...........
.............
...........
....................
INSTRUMENT SETUP COMMANDS AND REQUESTS
4.7.1 EOI Status - The ZN1 Command
4.7.2 Interface Mode
The MN1 Command
4.7.2.1 Local
COPYRIGHT 3/88 LSCI
4-2
4-7
4-7
4-7
4-7
4-7
4-7
iii
TABLE OF CONTENTS, CONT'D
4.7.3
4.7.4
4.7.5
4.7.6
4.8
....................
................
- The TN, Command . . . . . . .
. . . . . . . . .. .. .. .. .. ..... .. .. .. .. .. .. .... . .
.................
4.7.2.2 Remote
4.7.2.3 Local Lockout
Terminating Characters
Clear
The “W2” Data String
The “WI” Data String
S E C T I O N OF QUANTITIES FOR THE CONTROL AND SAMPLE DISPLAYS
UNITS. SENSORS. RESOLUTIONS AND DEVIATION (Table 4-7)
4.8.1 Units for Control Display and Set Point The FOC1 Command
The FlC1 Command
4.8.2 Units for Sample Display
4.8.3
Control Sensor Selection
The F2CC1N1 Command
The F2SC1N1 Command
4.8.4
Sample Sensor Selection
4.8.5 Resolution for The Control and Sample The F3CN1 and F3SN1 Commands
4.8.6 Selection of Deviation for Control and Sample The F4CON, F4COFF, F4SON and F4SOFF Commands
4.8.7 Selection of MATH Functions ON. OFF and CLEAR The F50N, F5OFF and F5CLR Commands
4.8.8 Sensor Curve # Selection
The NC1N1N2N3 Command
4.8.9 The A and B ID Information The AC1C2 and BC1C2 Commands
4.8.10 The “WD” Data String
-
...
-
..............
.....
....
....
........
.....
..........
...
........
-
4.9
.................
THE CONTROL COMMANDS . . . . . . . . . . . . . . . . . . . .
4.9.1 The Set Point Value - The S Command . . . . . . . . .
4.9.2
4.9.3
4.9.4
4.9.5
4.9.6
4.9.7
4.9.8
.............
...
.....
....
.............
........
.................
The “WP” Request Data String
Setting the GAIN (Proportional) - The P Command
Setting the RESET (Integral) The I Command
Setting the RATE (Derivative) The D Command
Heater Range
The R Command
% Manual Heater Power - The H Command
The “W3” Data String
-
...................
4.10 THE SCANNER INPUT CARD
4.10.1 SCAN Programming Instructions
4.10.2 Setting the Dwell Time The YAN1N2N3 and YBON2N3 Commands
4.10.3 Enabling the Scan Function
The YS Command
4.10.4 Holding the Scan Function - The YH Command
4.10.5 The W Y " Data String
.............
..........
.....
......
.................
4.11 THE SERVICE REQUEST. STATUS REGISTER. STATUS REPORTS
AND THE STATUS REGISTER MASK
4.11.1 The Service Request
4.11.2 The Status Register and Status Reports
4.11.2.1 Status Reports 0 and 1
Display and Control Data Ready
4.11.2.2 Status Report 2
The Control Channel Limit
................
.................
........
-
iv
-
. . . . . . ..
4-7
4-9
4-9
4-9
4-11
4-11
4-11
4-11
4-11
4-11
4-11
4-11
4-12
4-12
4-12
4-12
4-12
4-12
4-12
4-16
4-16
4-16
4-16
4-16
4-16
4-16
4-16
4-16
4-16
4-17
4-18
4-18
4-18
4-19
4-19
4-19
4-19
COPYRIGHT 3/88 LSCI
TABLE OF CONTENTS. CONT'D
4.11.2.3 Status Report 3-Display Sensor Channel Change
4.11.2.4 Status Report 5
Overload/Error Indicator
4.11.2.5 When operating without the Service Request
4.11.3 The Status Register Mask
The QC1C2 Command
4.11.3.1 Status Register Mask Bits 0 and 1 Display and Control Data Ready Enables
4.11.3.2 Status Register Mask Bit 2
The Control Channel Limit Enable
4.11.3.3 Status Register Mask Bit 3 Display Sensor Channel Change Enable
4.11.3.4 Status Register Mask Bit 5
Overload/Error Indicator Enable
4.11.3.5 Examples for setting Mask
4.11.3.6 Status Register Mask at Power Up
4.11.3.7 The “WQ” Data String
.
-
. . . . ..
...
......
....
.......
..........
. . . . . . .. .. .. .. .. ..
(INTERNAL) PROGRAMS . . . . .
-
4.12 SAVING AND RESTORING EXECUTABLE
4.12.1 Requesting a Program Step for Saving - WEN1N2 Command
4.12.2 Transmitting a Program Step to the 93C The ENN2 -C60 Command
4.12.3 Examples of Saving and Restoring
Executable (Internal) Program Steps
4.12.3.1 Program to Request and Store Program
Step # 1 t h r u 10 using the HP86B
4.12.3.2 Program to Restore Program Step # 1 thru
10 using the HP86B
4.12.3.3 National Instruments GWBASIC and BASICA IBM
Example of WEN1N2 Request
4.12.3.4 National Instruments GWBASIC and BASICA IBM
Example of E Command
4.12.3.5 National Instruments QUICK BASIC IBM
Example of WEN1N2 Request
4.12.3.6 National Instruments QUICK BASIC IBM
Example of E Command
C1
...........
.....
......
.............
..........
.............
..........
4.13
4.14
.............
COMMAND OPERATIONS . . . . . . . . . . . . . . . . . . . . . .
OUTPUT DATA STATEMENTS . . . . . . . . . . . . . . . . . . .
4.14.1 The “WS”, “WC” and “WP” Data Strings . . . . . . . . .
.................
SAMPLE PROGRAMMING . . . . . . . . . . . . . . . . . . . . .
4.15.1HP86B Keyboard Interactive Program . . . . . . . . . .
4.15.2 National Instruments GWBASICA or BASICA IBM Example .
4.15.3 National Instruments QUICK BASIC IBM Example . . . . .
4.15.4 HP86B Bus Commands Program . . . . . . . . . . . . . .
SENSOR CURVE PROGRAMMING INSTRUCTIONS . . . . . . . . . . . .
4.14.2 The “WO” Data String
4.15
4.16
. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
4.16.1 TheXDT Comand
4.16.2 The XDN1N2 Command
COPYRIGHT 3/88 LSCI
4-19
4-20
4-20
4-20
4-21
4-21
4-21
4-21
4-21
4-23
4-23
4-23
4-23
4-23
4-24
4-24
4-25
4-25
4-26
4-26
4-27
4-28
4-28
4-28
4-28
4-30
4-30
4-30
4-31
4-31
4-32
4-32
4-33
V
TABLE OF CONTENTS, CONT'D
4.16.3
4.16.4
4.16.5
4.16.6
4.16.7
SECTION V
5.1
5.2
5.3
5.4
5.5
5.6
5.7
. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..
..................
.................
The XDA Command
The XCN1N2 Command
The XEN1N2 Command
The XKN1N2* Command
The XAC1C2=N1N2* and XBC1C2=N1N2* Commands
......
- MAINTENANCE
........................
GENERALMAINTENANCE.. . . . . . . . . . . . . . . . . . . .
FUSE REPLACEMENT . . . . . . . . . . . . . . . . . . . . . .
LINE VOLTAGE SELECTION . . . . . . . . . . . . . . . . . . .
PERFORMANCE VERIFICATION . . . . . . . . . . . . . . . . . .
5.5.1
Performance Verification Connector . . . . . . . . . .
5.5.2
Performance Verification Procedure . . . . . . . . . .
CALIBRATION. . . . . . . . . . . . . . . . . . . . . . . . . .
5.6.1
Input Card Calibration . . . . . . . . . . . . . . . .
Set Point Voltage Calibration . . . . . . . . . . . .
5.6.2
Calibration of GAIN, RATE and RESET . . . . . . . . .
5.6.3
5.6.4
Calibration of Power Output . . . . . . . . . . . . .
TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . .
INTRODUCTION
SECTION VI
6.3
6.4
SUMMARY OF COMMANDS
6.2
6.5
INSTRODUCTION
.....................
INTERNAL PROGRAM ENTRY . . . . . . . . . . . . . . . . . . .
6.5.1
Starting the Program Edit Mode . . . . . . . . . . . .
6.5.2
Program Step Selection . . . . . . . . . . . . . . . .
6.5.3
Entering the Program Command and JUMP VECTOR,
6.5.4
6.5.5
6.5.6
6.5.7
6.5.8
vi
5-1
5-1
5-1
5-1
5-2
5-2
5-2
5-2
5-2
5-2
5-3
5-3
5-4
- PROGRAMMING INSTRUCTIONS
........................
PROGRAM STEPS AND SIZE . . . . . . . . . . . . . . . . . . .
PROGRAM STEP FORMAT . . . . . . . . . . . . . . . . . . . . .
6.1
4-36
4-36
4-37
4-37
4-37
..............
.....
REPEAT COUNT or RAMP COUNT
Entering the Setpoint, Gain, Rate and Reset
Entering Other Parameters
Entering the Timer Value
Entering the Program Step into Memory
Ending or Aborting the Programming Mode
..............
...............
. .. .. .. .. .. .. ..
6-1
6-1
6-1
6-1
6-3
6-3
6-3
6-4
6-4
6-4
6-4
6-4
6-4
COPYRIGHT 3/88 LSCI
TABLE OF CONTENTS, CONT'D
6.6
6.7
6.8
....................
CLEARING ALL INTERNAL PROGRAM MEMORY . . . . . . . . . . . .
EXAMPLES . . . . . . . . . . . . . . . . . . . . . . . . . .
6.8.1 Example #1 - Ramp and Soak . . . . . . . . . . . . . .
6.8.2 Example #2 - Ramp and Soak . . . . . . . . . . . . . .
6.8.3 Example #3 - Repeated Setpoint Ramp Up, Soak,
and Ramp Down with Gain Ramping . . . . .
6.8.4 Example #4 - Repeat of Example # 3 with a
L i m i t of 10 Cycles . . . . . . . . . . .
RUNNING THE PROGRAM.
- ACCESSORIES, INPUT CARDS AND
APPENDIX A - Standard Curve Data
APPENDIX B - Sensor Curve Information
SECTION VII
APPENDIX C
- Error Code
COPYRIGHT 3/88 LSCI
6-4
6-5
6-5
6-5
6-6
6-7
6-8
OPTIONS
Summary
vii
L I S T
SECTION I
-
Table 1-1.
SECTION II
Table
Figure
Table
Figure
Table
Table
O F
T A B L E S
A N D
I L L U S T R A T I O N S
GENERAL INFORMATION
Specifications, Model DRC-91C Temperature Controller
-
INSTALLATION
..
................
..............
...
..................
...............
........
2-1. Line Voltage Selection
2-1.
2-2.
2-2.
2-3.
2-4.
Typical Rack Configuration
INPUT Connections for J1 INPUT A and J2 INPUT B
Sensor Connections
J3 MONITORS Connections.
REMOTE SENSOR ID Connector Assignments
SECTION III
-
3-1.
3-1.
3-2.
3-3.
SECTION IV
Table
Figure
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Table
Figure
Table
Table
Table
Table
viii
4-1.
4-1.
4-2.
4-3.
4-4.
4-5.
4-6.
4-7.
4-7.
4-8.
4-9.
4-10
4-11
4-2.
4-12
4-13
4-14
-
2-1
2-2
2-2
2-2
2-3
2-4
OPERATING INSTRUCTIONS
.....
.....
..............
................
..............
.....
DRC-93C Temperature Controller - Front Panel
System Resolution Versus Sensor Sensitivity
Standard Curve Information
Sensor Curve Table Information
Precision Option Table
Table 3-4. Correlation Table for Curve #
from REMOTE POSITION DATA
Figure 3-2. DRC-93C Temperature Controller - Rear Panel
Table 3-6. Pin Assignments for the J5 REMOTE SENSOR ID Connector
Figure
Table
Table
Table
1-4
REMOTE OPERATION
.................
.......
.......
................
.....
..........
.
.....
.....
.....
......
..
..
.
.......
.
...
.............
Interface Functions.
IEEE-488 Address Switch for the DRC-93C
Allowable Address Codes for the DRC-93C
IEEE-488 Bus Commands
DRC-93C Command Summary of Instrument Setup
DRC-93C Summary of Output Requests
DRC-93C Interface Setup Commands and Request Status
DRC-93C Command Summary for Instrument Setup
DRC-93C Request Summary for Instrument Setup
C1 and C2 in A ID and B ID, the SENSOR ID's.
DRC-93C Command Summary for Setpoint Setup
DRC-93C Command/Request Summary for Control Setup
DRC-93C Command/Request Summary for Scanner Setup
93C Status Register MASK and Status Register Format
Commands to Fix the Status Register Mask
93C Command/Request Summary for Status Register Mask
DRC-93C Command/Request Summary for Program Step
4-15 DRC-93C Output Data Requests
3-4
3-8
3-10
3-10
3-13
3-18
3-19
4-2
4-3
4-4
4-6
4-8
4-9
4-10
4-13
4-14
4-14
4-15
4-17
4-18
4-22
4-22
4-23
4-24
4-29
COPYRIGHT 3/88 LSCI
TABLES OF TABLES AND ILLUSTRATIONS, CONT'D
Table
Table
Table
Table
4-16
4-17
4-18
4-19
SECTION VI
Table
Table
6-1.
6-2.
........
Sensor Curve Commands and Description
Sensor Curve Information T a b l e O u t p u t Format
XDN1N2 Sensor Curve output Format
C o n v e r s i o n of Raw U n i t s D a t a for the XC Command
-
.....
..........
...
4-34
4-35
4-35
4-38
.................
...............
6-1
6-2
PROGRAMMING INSTRUCTIONS
ProgrammerS u m m a r y .
PROGRAMMING COMMANDS..
COPYRIGHT 3/88 LSCI
ix
S E C T I O N
G E N E R A L
1.1 INTRODUCTION
The information contained in this
operations manual pertains to the
installation, operation, remote
programming, options and accessories for the Lake Shore Cryotronics, Inc. Model DRC-93C Temperature Controller. This manual also
contains troubleshooting and
calibration procedures, schematics,
component layouts and replaceable
parts lists.
This section contains general
information for the Lake Shore
Cryotronics, Inc. DRC-93C Temperature Controller.
Included is an
instrument description, specifications, instrument identification,
option and accessory information.
1.2 DESCRIPTION
The DRC-93C Temperature Controller
is a microprocessor based instrument which provides true analog
control. It is capable of scanning
multiple sensor inputs and displaying temperature with up to 5 digits
of resolution in K, OC or OF or
sensor units (volts, ohms or
nanofarads) to five digits.
The DRC-93C can be used with either
1 or 2 input cards. When two input
cards are used, these cards can be
different to allow two separate
types of sensors to be used with
the controller.
The dual sensor input with the
optional 8229 Scanner Conversion
Card expand the input capability of
the DRC-93C to up to 6 input
sensors.
Depending on the input
option selected, the DRC-93C
handles silicon (9210-3 or 9220-3)
or the patented Gallium-AluminumCOPYRIGHT 3/88 LSCI
I
I N F O R M A T I O N
Arsenide (9210-6 or 9220-6) diodes,
platinum or rhodium-iron resistors
(9220 series), germanium or carbon
glass resistors (9317C, 9318C), or
capacitance sensors (9215).
With or without the 8229 Scanner
Card, the DRC-93C can be set to
scan automatically with an individual dwell time of 1 to 99
seconds per channel or stepped to
any available input and held there.
Setting the dwell time to zero
causes a particular channel to be
skipped.
If all dwell times are
zero, the instrument stays on the
channel selected.
The DRC-93C gives a direct reading
in temperature when used with any
DT-470 Series Temperature Sensor.
All DT-470 Sensors follow the same
temperature response curve. Four
bands of tracking accuracy are
available.
Refer to DT-470
technical data for details.
Diode sensor voltages are digitized
to a resolution of 100 microvolts
with full scale dependent on input
card configuration. The temperature display has a resolution
capability of 0.01 kelvin above 100
kelvin and 0.001 kelvin below 100
kelvin.
For greater precision individual
sensor calibrations can be accommodated with the 8001 Precision
Calibration Option which programs
the instrument with calibration
data for a specific Sensor. The
algorithm within the instrument
interpolates between data points to
an interpolation accuracy which
exceeds 0.01K over the entire
temperature range of the Precision
option.
The 16 bit analog-todigital converter is accurate to
1-1
Section 1
plus or minus the least significant
bit, which for the 470 series
sensor results in an uncertainty of
l m K below 28K and 45mK above 40K
with a transitional region between
these two temperatures. Therefore,
at temperatures below 28K, the
overall system accuracy, the sum of
the instrument accuracy (1lmK) and
that of the calibration itself
(Lake Shore calibrations are
typically better than 20mK within
this region) is & 30mK. Above 28K,
system accuracy gradually moderates
to a typical value of +75mK above
40K.
See the Lake Shore IDW
Temperature Calibration Service
brochure for additional discussion
of calibration accuracy.
The Model DRC-93C can also be used
with the 9220 input card which
handles both diodes and positive
temperature coefficient metallic
resistors., i.e., platinum or
rhodium-iron resistors.
The DIN
curve is standard within the
instrument and is called up
automatically unless a positive
temperature coefficient precision
option curve is selected for that
input. The accuracy of the reading
is dictated by the sensor and its
conformity to the DIN curve. The
tolerance on these devices is given
on the technical data sheet for the
Lake Shore PLATINUM RTD's.
The
combined accuracy of the instrument
and a calibrated resistor with a
precision option is on the order of
40mK over the useful range of the
sensor (above 40K for the platinum)
Note that a precision
option is required for a rhodiumiron to read correctly in temperature
.
.
The Model DRC-93C with the 9318C
germanium/carbon-glass input card
results in the most accurate system
below 50K in temperature. For both
sensors, a precision option is
required to read in temperature.
Near 4K, the overall accuracy of
the system, including the calibra1-2
Model DRC-93C
tion accuracy, the software
interpolation accuracy and the
calculation of the resistance
results in an overall accuracy on
the order of 10mK.
These input option cards are easily
installed by the user; thus, units
can be changed or upgraded to
satisfy changing requirements.
The ample memory space provided in
the DRC-93C allows several response
curves to be stored in the instrument. Depending on the complexity
of the curves, up to 25 can be
programmed into the unit.
The
active curve is selected either
from the front panel or over the
remote interface.
The data for calibrated sensors can
be stored in the instrument as an
8001 Precision Option or by the
customer via the front panel or
remote interfaces.
These curves
can contain up to 99 sensor
temperature data points. With the
standard precision option format of
31 data points and an 18 character
information line, up to twenty
curves can be stored.
Although data points are stored as
a table, the interpolation
algorithm used results in the
equivalent of a high order
Chebychev polynomial calculation in
the converting
of the input
voltage (or resistance) to temperature. This is done by means of a
proprietary algorithm developed at
Lake Shore Cryotronics.
An averaging algorithm can be
selected to average up to ten
temperature readings.
This mode
eliminates noise within the system
analogous to averaging with a
digital voltmeter. This averaging
mode can be disabled from the front
panel or over the remote interface
for a given input if the customer
prefers not to average readings.
COPYRIGHT 3/88 LSCI
Section I
Model DRC-93C
The control set point is also
displayed on the front panel and
can be set from the front panel.
The set point automatically takes
on the units selected for the
control sensor. In the units mode
the set point can be set to five
digits with the range of defined by
the control sensor input card. The
standard set point temperature can
be set to 0.1 degree.
This
temperature is converted to an
equivalent voltage with a resolution of 100 microvolts out of 3
volts full scale.
The optional
High Resolution Set point expands
the set point resolution to 0.01
degrees 100 and 0.001 degrees below
100.
The equivalent voltage is
expanded to 25 microvolts out of 3
volts full scale. This results in
a settability of approximately 0.01
kelvin above 40K and 0.001 kelvin
below 28K for the DT-470 series
sensors.
The control section of the DRC-93C
provides three-term temperature
control.
Proportional (GAIN),
integral (RESET) and derivative
(RATE) are individually set with a
range from 0.1 to 99 resulting in a
990 to 1 range.
Heater power output of the DRC-93C
Temperature Controller is a maximum
of 50 watts when a 50 ohm heater is
used. A digital bar graph on the
front panel displays the output as
a percentage of output range
selected. Thus, the user can conveniently monitor power applied to
his system. To accommodate systems
which require lower heater power,
the maximum output can be attenuated in four steps of a decade
each. Three resistance ranges are
available; 0-25, 25-35 and 35-50
Ohms.
The desired range is selected by a
slide switch on the rear panel.
The power must be off for this
selection, since the transformer
output is shorted momentarily by
COPYRIGHT 3/88 LSCI
changingthe setting.
The maximum power can also be
limited by using the rheostat on
the rear panel.
Power can be
reduced on the MAX scale to any
value between MAX and a reduction
of a factor of ten in power.
When greater output power is
required, the optional W60 output
stage can provide 60 watts into a
25 ohm load.
An IEEE-488 interface is standard
in the DRC-93C. This interface can
be used to remotely control all
front-panel functions.
When two
input cards are used, data from
both inputs is available via the
interface.
1.3 SPECIFICATIONS
Instrument specifications are
listed in Table 1.1.
These
specifications are the performance
standards or limits against which
the instrument is tested.
1.4 OPTIONS
The options for the DRC-93C
Controller are listed in Section
VII.
Three option ports are designed
into the DRC-93C. The options are
field installable by the user.
822x-series options can be factory
installed in the DRC-93C or fieldinstalled at a later the.
The
8223 RS-232C Interface Option
operates similar to the IEEE-488
interface.
With the display in
temperature units, the Model 8225
Analog Output option is available
to provide a linearized analog
output of 10mV/K independent of the
display temperature units chosen.
If the display is in sensor units,
the output for diodes is lV/V; for
100 ohm platinum, 10mV/ohm; for
1000 ohm platinum, lmV/ohm; for
1-3
Section I
rhodium-iron, 100mv/ohm; and for
capacitance units, 100mV/nF and
10mV/nF. Since the 9317C and 9318C
vary over such a large range of
resistance, use of the 8225 with
these two input cads is limited to
10mV/K. The Model 8229 Scanner
Table 1.1.
Inputs: Two Sensor Inputs, A and
B.
The 8229 Scanner Conversion
Option provides for four additional
channels of Sensor Input. Display
sensor can be selected from front
panel or interface, or display can
be set to scan between sensor
inputs. Dwell t h e per channel can
be set independently from 0 (skip)
to 99 seconds. Input characteristics are a function of Sensor Input
Option Installed. The DRC-93C can
accomodate two input options which
allows the A input and the B input
to each be assigned their own input
card. This allows concurrent use
of different sensor types, dependent on the user's application.
Ordered Separately. DRC93C will handle all types of
diodes; germanium, carbon glass,
carbon, etc. negative temperature
coefficient resistors; thermistors;
platinum, rhodium-iron, etc.
metallic resistors as well as
capacitance thermometers with
proper choice of input option
cards.
See the Lake Shore
Cryotronics, Inc. Sensor catalog
for details on the above Sensors.
Sensors:
Display Readout:
5-digit LED Display of
Sensor reading in Sensor Units
(Volts, Ohms or Nanofarads) or
temperature in K, °C, or OF shown
with annunciators.
1-4
Option provides four additional
channels of sensor input to the “A”
input. The A input is channel A
with the additional inputs designated 1-4 with the selection
indicated on the display.
Specifications, Model DRC-93C Temperature Controller
Input characteristics:
Display:
M o d e l DRC-93C
Resolution:
Display resolution is
0.001K below 1 0 0 K , 0 . 0 1 K above 100K
(0.0001K below 1 0 K for 9317C
Resistance Sensor Input Card).
Resolution can be user-limited to
1K, 0.1K or 0.01K.
Same resolution
considerations apply for °C and °F.
Changes made by front panel keys or
over interface.
Temperature Accuracy:
Dependent on
Sensor Input Card and Sensor. See
Input Options available.
Temperature Range:
Dependent of
Sensor Input Card and Sensor.
Temperature Control:
Set Point:
Keypad selection as a
numeric value, as a step change
from prior value, or incrementally
via up/down counter.
All keypad
operations can be duplicated with
optional interfaces.
Set Point Resolution: Selection in
kelvin, Celsius, fahrenheit or
Sensor Units. Temperature to 0.1
in corresponding units; in Sensor
Units, 0.1mV in voltage, 0.01 ohms
but limited to five digits in
resistance and 0.001 nanofarads out
of 15 nanofarads (0.01 nanofarads
out of 150 nanofarads for second
scale) in capacitance. May also be
set over the interface.
Typical Controllability:
Dependent
on Sensor, its temperature and the
resultant Sensor “gain”, i.e.,
sensitivity. Typically better than
1mK in a properly designed system
below 30K and 5mK above 30K using a
COPYRIGHT 3/88 LSCI
Section 1
Model DRC-93C
D i o d e Sensor.
But, f o r example, a
thermistor,
due t o i t s large
s e n s i t i v i t y , may r e s u l t i n a
c o n t r o l l a b i l i t y approaching 0.5mK
above 2 0 0 K over a narrow temperat u r e range i n c e r t a i n systems and a
germanium below 1 0 K may control t o
0.1mK i n another system.
Control
Proportional
integral
(RESET)
and
derivative (RATE). Set numerically
(0.0
t o 99. of i n t e r n a l l y established range) o r incremented v i a
front-panel
keypad.
Continuous
two-digit display of each mode.
Manual M o d e allows 0 t o 100% of
a v a i l a b l e heater power t o be
selected v i a keypad.
Auto and
Manual modes can be used concurrently. A l l keypad. operations can
be duplicated t h r u interfaces.
Modes:
(GAIN),
output:
Up t o 50 w a t t s
(1A,
50V)
standard.
Five output
ranges can be selected either from
front-panel
o r i n t e r f a c e and
provide approximate decade s t e p
reductions of maximum power output.
Optional 60 w a t t output available.
Rear panel maximum current l i m i t
f o r MAX scale.
Heater
BAR display
continuously shows heater current
o r power output as a percentage of
range w i t h a resolution of 1%.
H e a t e r output M o n i t o r :
Control Sensor:
E i t h e r Sensor
Input (selected from f r o n t panel o r
remote interfaces)
.
General:
Sensor V o l t a g e Monitor:
For 9210
Option, buffered output of each
COPYRIGHT 3/88 LSCI
diode sensor voltage.
For 9220
Option diode configurations (-3,-6)
g i v e buffered output of diode
s e n s o r ; f o r -6
configuration,
b u f f e r is 0 . 4 5 8
t i m e s sensor
voltage; f o r 9220 Option positive
temperature c o e f f i c i e n t conf igurations (-P2, -P3, -R1) , buffer is
sensor voltage output times -10.
For 9215, signal is proportional t o
capacitance value; f o r 9 3 1 7 C o r
9318C, monitor not of use.
Response time (electronics): Less
than 1 second t o rated accuracy f o r
non-Lagrangian
calculations.
Lagrangian curves r e s u l t i n update
t i m e s between one and two seconds.
Three readings on channel change o r
r a n g e change t o reach rated
accuracy.
IEEE-488 Interface: Allows remote
control of set-point, gain, r a t e ,
reset, u n i t s and heater power
range.
Provides output of display
i n u n i t s chosen, u n i t s and a l l
f r o n t panel functions (except power
on/off).
Allows input of curve
data f o r calibrated sensors and
i n t e r n a l ramping programs.
D i m e n s i o n s , Weight:
432m wide x
102mm high x 330mm deep (17in. x
4in. x 13in.) S t y l e L, full-rack
package. N e t weight 8kg (17 1b.).
Power: 90-110, 105-125, o r 210-250
VAC (selected via rear panel w i t h
instrument o f f ) , 50 o r 60 Hz, 75
watts.
Accessories Supplied:
Mating
connector f o r sensor/monitor
connector, instruction manual.
1-5
repackaging instructions.
2.2 I N I T I A L INSPECTION
This instrument was electrically,
mechanically and functionally inspected prior to shipment.
It
should be free from mechanical
damage, and in perfect working
Line Voltage (Volts)
100
120
220
240
COPYRIGHT 3/88 LSCI
Verify that the AC Line Voltage
Selection Wheel (Figure 3-2,Key 1)
located on the rear panel of the
Model DRC-93C is set to the AC
voltage to be used (Table 2-1) and
that the proper fuse is installed
before inserting the power cord
and turning on the instrument.
Operating Range (Volts)
90-105
108-126
198-231
216-252
Fuse (A)
11-
2
2
SB
SB
SB
SB
2-1
Section II
Figure 2-1.
2.3.4
Typical Rack Configuration
Bench U s e
The DRC-93C is shipped with plastic
“feet” and a tilt stand installed
and is ready for use as a bench
instrument. The front of the instrument may be elevated for convenient operation and viewing by
extending the tilt stand.
2.3.5
RackMounting
The DRC-93C can be installed in a
standard 19 inch instrument rack by
using the optional RM-3F or RM-3FH rack mounting kit. A typical RM3F-H kit installation is shown in
Figure 2-1.
2.3.6
The
pin
The
the
and
Sensor Input Connections
DRC-93C has two rear panel 5input connectors for sensors.
lead connection definition for
sensor(s) is given in Table 2-2
is shown in Figure 2-2.
Table 2-2. INPUT Connections
for J1 Input A and J2 Input B
Terminal
A
B
D
E
H
2-2
Description
+ Current Out
- Current Return
- Voltage Sense
+ Voltage Sense
Shield
Model DRC-93C
The use of a four lead connectio
arrangement (a) is required for
four lead sensor.
Figure 2-2.
Sensor Connections
A (+I)
E (+V)
(a)
Lead Sensor,
Lead Hook-up
e.g. Germanium, CarbonGlass, Rhodium-Iron
D (-V)
4
4
B (-I)
A (+I)
E (+V)
(b) 2 Lead Sensor,
4 Lead Hook-up
e.g. Platinum, Silicon
Diode
D (-V)
B (-I)
A (+I)
E (+V)
(c) 2 Lead Sensor
2 Lead Hook-up
e.g. Silicon Diode
D (-V)
B (-I)
S
E
N
S
O
R
S
E
N
S
O
R
S
E
N
S
O
R
The use of a four wire connection
(Figure 2-2a and b) is highly reCOPYRIGHT 3/88 LSCI
Section II
M o d e l DRC-93C
commended for resistive elements to
avoid introducing IR drops in the
voltage sensing pair which translates into a temperature measurement error.
T a b l e 2-3.
An alternate two line wiring method
(Terminals A and E shorted together, B and D shorted) may be used
for the DT-470 and TG-120 series
diodes in less critical applications where lead resistance is
small and small readout errors can
be tolerated (c).
Measurement
errors due to lead resistance for a
two lead hook-up can be calculated
using; §T = IR/[dV/dT] where I is
10 microamperes, R is the total
lead resistance; dV/dT is the diode
sensitivity and §T is the measurement error. For example, R = 250
ohms with dV/dT = 2.5 millivolts/kelvin results in a temperature error of 1 kelvin. Two wire
connections are not recommended for
other sensor types.
C
The Lake Shore Cryotronics, Inc.
QUAD-LEAD™ 36 Gauge Cryogenic wire
is ideal for connections to the
sensor since the four leads are run
together and color-coded. The wire
is Phosphor Bronze with a Formvar
insulation and Butryral bonding
between the four leads. Color coding is red, green, clear and blue
on the four leads which makes it
extremely easy to determine one
wire from another.
2-3.7 J3 Sensor Output MONITORS
Buffered voltage outputs for both
Sensor Input A and B are available
on the J3 connector on the back
panel of the instrument. The voltage from the Model 8225 Analog
Output Option is present on this
connector also. The connector pin
assignments are given in Table 2-3.
COPYRIGHT 3/88 LSCI
Terminal
A
B
D
E
F
H
2.3.9
J3 MONITORS Connections
Description
Voltage Output (Input A)
Voltage Output (Input B)
10 mV/K Analog Output
Ground for Analog Output
Setpoint Output
Ground (A, B,Setpoint)
(Optional Shield)
Heater Power
The heater output leads should be
electrically isolated from the sensor(s) ground(s) to preclude the
possibility of any of the heater
current affecting the sensor input
signal.
The heater leads should
not run coincident with the sensor
leads due to the possibility of
capacitive pick-up between the two
sets of leads.
If they are in
close proximity, they should be
wound so as to cross the sensor
leads at ninety degrees if at all
possible.
The heater output is a current
drive and does not have to be
fused. The DRC-93C is designed to
power a 50 ohm heater for maximum
heater output. If a smaller resistance is used, the maximum heater
power corresponds to the heater
resistance, i.e., 10 ohms yields 10
watts. A larger heater can also be
used. Since the compliance voltage
is 50 volts; a 100 ohm heater will
allow a maximum power output of 25
watts [ (50)2/100].
slide switch on the back panel
sets the available output power
dependent on the value of the
heater resistance.
This slide
switch must only be changed with
the instrument turned off since it
shorts the windings of the output
A
2-3
Section II
Model DRC-93C
transformer between positions.
The setting range of the switch
should coincide with the heater
resistance to minimize power dissipated within the DRC-93C. Three
setting ranges are available: 1025, 25-35 and 35 to 50 ohms.
optional output power stage
(W60) of 60 watts is available for
the DRC-93C. The W60 is rated at
1.5 amperes at approximately 43
volts (into 25 ohm load).
An
REMOTE SENSOR ID Interconnecting
Cable and REMOTE SENSOR ID connector assignments are given in Table
2-4.
Table 2-4.
REMOTE SENSOR ID
Connector Pin
Function
10
8
6
4
14
12
A 50 ohm, 50 watt (1/4" dia. x 1"
long) cartridge heater is available
as well as a 25 ohm, 25 watt (3/8"
dia. x 1” long) cartridge heater.
30 gauge stranded copper lead
wire (ND-30) is recommended for
connecting to the heater.
A
2.3.9.1
MAX HEATER POWER L i m i t
Make sure that the MAX HEATER POWER
limit potentiometer is turned fully
clockwise during the setup of the
instrument so that full power is
available on the MAX power scale,
if desired.
2.3.9.2
Display
Current
or Power Output
The HEATER % meter can be set to
read either % of output power or %
of output current.
The internal
DIP switch setting (switch 1) controls whether the meter reads in %
current (closed) or % power (open).
The DRC-93C is shipped to read in %
power.
2.4 REMOTE SENSOR I D Connector
The REMOTE SENSOR ID connector, J5,
on the rear panel receives POSITION
DATA from a Model 8084 or 8085
Sensor Scanner or a Model SW-10A
Ten-Sensor Selector Switch.
The
2-4
REMOTE SENSOR I D
Connector Assignments
Bit 0 (BO-LSB)
Bit 1 (B1)
Bit 2 (B2)
Bit 3 (B3)
Bit 4 (B4-MSB)
Digital Ground
The POSITION DATA is the binary
representation of the remote position. Table 2-4 gives the POSITION
DATA binary combinations and
equivalent hexadecimal remote position. The remote position input
can be used to select specific
sensor curve tables stored in the
DRC-93C.
The correlation between
remote position and sensor curve is
given in Section III.
2.5
IEEE-488 INTERFACE Connector
The IEEE-488 Connector on the back
of the DRC-93C is in full compliance with the IEEE Standard
488-1978. The connector has metric
threaded mounting studs, visually
indicated by the color black.
Metric threaded cable lockscrews
(also black) must be used to secure
an IEEE-488 interface cable to the
instrument.
Model 8072 IEEE-488
Interconnect Cables (one meter
long) are available from Lake
Shore.
COPYRIGHT 3/88 LSCI
Model DRC-93c
Section II
2.6 Options
.
2 6.1
8223
2.7 ENVIRONMENTAL REQUIREMENTS
Rs-232C
Interface.
Provides remote operation of the
same parameters as the IEEE-488.
The RS-232C interface option is
described in Section VII of this
manual including connections.
2.6.2 8225 Analog Output. Provides
analog output proportional to kelvin temperature f display sensor
(10mV/K) at <10 ohms output resistance. The 8225 Analog Output is
described in Section VII of this
manual.
2.6.3
8229 Scanner Input Option.
Adds four additional channels to
the “A” input.
Scans up to six
sensors with programmable dwell
times. The 8229 Scanner Option is
described in Section III and
Section VII of this manual.
2.6.4 The High Resolution S e t Point
expands the set point resolution to
0.01 kelvin above 100K and 0.001
kelvin below 100K. The equivalent
voltage is expanded to 25 microvolts out of 3 volts full scale.
This results is a setability of
approximately 0.01 kelvin above 40K
and 0.001 kelvin below 28K for the
DT-470 series sensors.
2.6.5
8001 Precision Option.
Cus-
tom programming of specific Sensor
calibration curve(s) at factory.
Provides highest degree of readout
accuracy.
2.6.6
The W60 Output Option will
deliver 60 watts at 1.5 amperes at
approximately 43 volts into a 25
ohm load.
This is a factory
installed option.
COPYRIGHT 3/88 LSCI
WARNING
To prevent electrical fire or
shock hazards, do not expose
the instrument to rain or
excess moisture.
2.7.1
Operating Temperature
In order to meet and maintain the
specifications in Table 1-1, the
DRC-93C should be operated at an
ambient temperature range of 23°C ±
5°C.
The unit may be operated
outside the range of 15-35°C with
less accuracy.
2.7. 2 Humidity/Altitude
The DRC-93C is for laboratory use
and no humidity or altitude specifications have been determined for
this unit.
2.8 REPACKAGING FOR SHIPMENT
If the Model DRC-93C appears to be
operating incorrectly, refer to the
Troubleshooting Guide in Section
5.7.
If the tests indicate that
there is a fault with the instrument, contact Lake Shore or a factory representative for a returned
Goods Authorization (RGA) number
before returning the instrument.
when returning an instrument for
service, photocopy and complete the
Service Form found at the beginning
of Appendix A.
The form must be
filled in to ensure efficient solution of the problem. The following
information must be provided before
Lake Shore will attempt any repair.
2-5
Section II
Model DRC-93C
1. Instrument Model and Serial # s
2.
3.
4.
5.
User ‘s Name, Company, Address,
and Phone Number
Malfunction Symptoms
Description of system
Returned Goods Authorization No.
I f the original carton is available, repack the instrument in a
plastic bag, place it in the carton
using original spacers to protect
protruding controls.
Seal the
carton with strong paper or nylon
tape. Affix shipping labels and
“FRAGILE” warnings.
the original carton is not
available, pack the instrument
similar to the above,, procedure,
being careful to use spacers or
suitable packing material on all
sides of the instrument.
If
2-6
COPYRIGHT 3/88 L S C I
S E C T I O N
O P E R A T I N G
I N S T R U C T I O N S
3.1 INTRODUCTION
This section contains information
and instructions concerning the
operation of the Model DRC-93C Temperature Controller. Included is a
description of the front and rear
panel controls and indicators.
3.2 INSTRUMENT CONFIGURATION
3.2.1
Input Card Configurations
The Model DRC-93C can be used with
either one or two input cards. The
input cards available for use with
the DRC-93C are summarized in Section I. The input cards available
allow the 93C to be used with almost
any type of cryogenic sensor. Input
cards can be mixed, allowing two
different sensor types to be used
with the DRC-93C.
3.2.2
Single Input Card
When only one input card is present
within the unit, it occupies the
INPUT CARD #1 slot of the DRC-93C
mainframe and is connected to the
Sensor A input of the controller.
Only one sensor can be used with the
controller under these conditions.
3.2.3
D u a l Input Cards
When two input cards are present in
the unit, the input card that occupies the INPUT CARD #1 slot is
routed to the Sensor A input and the
input card that occupies the INPUT
CARD #2 slot is routed to the Sensor
B input. Consequently, both sensors
are energized at all times.
The second input card allows the
instrument to mix sensor types,
COPYRIGHT 3/88
III
e.g., both a diode thermometer and a
resistance thermometer can be used
on the two inputs. Another possibility with the 9318C and 9220 Options
would be the presence of a GR-200A
Series Germanium Sensor as well as a
PT-100 Series Platinum Resistance
Sensor.
Both inputs are updated
independently, which allows them
both to be displayed or queried
under IEEE-488 or RS-232C control.
The addition of an optional 8229
Sensor Scanner Card adds capability
for 4 additional inputs to the A
channel resulting in up to 5 sensors
of the same type being allowed using
the A input card.
3.2.4
Old Version Input Cards
The 8210, 8211 diode input cards can
be used in the 93C as well as the
8219 series resistance input card.
The installation of these cards is
covered in Section 7-3 of this
manual.
Note that there are Dip
Switch settings on the main board
which must be set in order for these
older cards to work properly.
3.3 CURVE ENTRY
The DRC-93C allows the user to enter
his own sensor calibration via the
front panel or over the remote interface.
Section 3.9.3 discusses
curve entry via the front panel and
Section IV covers entry over the
IEEE-488
or RS-232C interfaces.
The curve is stored in a battery
back-up non-volatile RAM (NOVRAM)
which can be read and written an
unlimited number of times. The number of data points stored per curve
can be between 2 and 97; two being
the lower limit which defines a
straight line.
3-1
Section III
Model DRC-93C
3.4 PRECISION OPTIONS
3.4.1 The Model 8000 Precision
option
There are three types of Precision
Options available for the DRC-93C.
The Model 8000 Precision Option
generates the data table from a Lake
Shore calibrated sensor. The upper
limit of data points is again 97,
with a typical calibration ranging
between 30 and 40 points, depending
on sensor type and temperature range
for the calibration. The data and
accuracy of the fit is supplied to
the user as a separate document.
This information can then be entered
by the user via the front panel or
over the computer interface.
3.4.2 The Model 8001 Precision
option
Lake Shore can also generate custom
sensor response curves from the individual sensor calibrations as
indicated above and store them in
the DRC-93C via the 8001 Precision
Option prior to shipment. The data
and accuracy of the fit is then
supplied to the user in an Appendix
of this manual.
3.4.3
option
The Model
8002-05
Precision
and with which input the sensor will
be associated if remote operation is
used.
3.5 CONTROL FUNDAMENTALS
An application note entitled
“Fundamentals for Usage of Cryogenic
Temperature Controllers" is included
as an appendix in this manual and
should be read in detail if you are
not familiar with cryogenic temperature controllers.
3.6 CONTROLS AND INDICATORS
Figures 3-1 and 3-2 identify the
DRC-93C displays, annunciators, controls, and connectors. The identification of each item is keyed to
the appropriate figure.
FRONT PANEL DESCRIPTION
3.7 POWER ON
Before connecting AC power to the
DRC-93C, make sure the rear panel
voltage selector is set to correspond to the available power line
voltage.
Be certain the correct
fuse is installed in the instrument.
3.7.1
Power Up Sequence
The 8002 Precision Option is used
when the customer already owns a
DRC-93C and wants new sensor calibration data stored in the instrument. LSCI stores the calibration
data in a PROM chip and sends the
programmed chip to the customer.
The PROM is then installed in the
DRC-93C by the customer.
All digits, annunciators, and the
bar graph turn on to test the
lights.
Note that additional calibrations
can be added to the instrument at a
later time by specifying with the
sensor calibration at time of order,
the serial number of the instrument
The TEMPERATURE Block indicates
+8.8.8.8.8. in both the upper,
lower and setpoint windows.
The
CONTROL Block indicates 8.8. in the
GAIN, RATE, and RESET windows. The
3 -2
Immediately on POWER ON the DRC-93C
runs through a power up sequence as
follows:
1. Light Test
COPYRIGHT 3/88
Model DRC-93C
Section III
HEATER POWER Bar Graph indicates
100%. The UPPER and LOWER DISPLAY
SENSORS have 8. The indicators for
the six sets of UNITS for both the
Upper and Lower displays are displayed to the far left of the front
panel.
The control (CTRL) annunciators are between the SENSOR annunciators. The RANGE from OFF to
MAX annunciators are below the Bar
graph and the LOCAL, REMOTE, PROG
(programming) and INT (internal
program) to the far right of the
front panel.
2. Instrument Name and IEEE Address
Next the unit displays LSCI in the
Upper Display, -93C- in the Setpoint
Display and the IEEE-488 interface
address in the Lower Display. For a
factory set IEEE address of 12 the
display would indicate Add12. This
address can obviously be changed by
the user and verification of that
change is always given on power-up.
Note that this address is only read
by the instrument on power-up
3.
Input Card Configuration
The unit then displays the input
cards associated with the inputs on
the upper and the lower displays.
4.
Normal Operation
The unit then goes
operation.
3.7.2
into normal
Power-up Status
A provision has been made to store
parameter changes in the DRC-93C
memory (NOVRAM)
The sample and
control units, as well as the curve
numbers and scan dwell times can be
stored as power-up settings. When
enabled, any time the parameter is
changed, either in the LOCAL or
REMOTE mode, the NOVRAM is updated.
The internal DIP switch setting
.
COPYRIGHT 3/88
(switch 2) controls whether or not
the settings are updated. The updating is enabled (switch 2 on) at
the factory prior to shipment.
3.7.3
B l u e Legend K e y s
At the beginning of an operation, if
one of the grey keys of the keypad
with Blue Legends (also labelled 09, and .) is pressed, the function
described by the blue legend is immediately displayed or carried out.
These functions are SENSOR, UNITS,
CURVE#, RSLTN, FILTER, CONTROL, DEV,
MATH, MAX, MIN, MAXDEV.
The CURVE#, RSLTN, FILTER, DEV,
MATH, MAX, MIN, and MAXDEV keys must
be held down in order to observe the
For exquantity continuously.
ample, if the RSLTN (resolution) key
is pressed, the display will immediately show the resolution assigned to the Upper and Lower Displays.
When the key is let up,
operation will return to normal
operation with the displays showing
temperature, voltage, etc.
The CONTROL, SENSOR, UNITS, CURVE#,
RSLTN, FILTER, DEV, and MATH keys
provide operations that can be
changed by the user. The
(up)
and
(down) keys are used in conjunction with these Blue Legend keys
to alter the quantity with the
key referring to the Upper Display
and the
key referring to the
Lower Displays. In order to change
one of these quantities it is necessary to hold the Blue Legend key
down while hitting the
(up) key
or
(down) key. The
key will
change the entry of the Upper display and the
key will change the
Lower display.
3-3
Section III
Figure 3-1.
Model DRC-93C
DRC-93C Temperature Controller
Front Panel
Figure 3-1- Model DRC-93C Temperature controller
Front Panel Description
U p p e r and laver Displays
1.
2.
3.
10.
Sensor reading in temperature
(Kelvin, Celsius, or Fahrenheit), or sensor units (Voltage, Resistance, Capacitance)
Sensor No. (A, b, 1, 2, 3, 4).
Annunciators indicating units
of Sensor (K, F, C,
V, N).
.
S e t Point
4.
5.
(control) Arrow Annunciator indicating whether the
sensor in the Upper or Lower
Display is the control sensor.
Display of Set Point in temperature (kelvin, celsius, or
fahrenheit), or sensor units
(voltage, resistance or capacitance) in the units of the
Control Sensor (as indicated by
CTRL Arrow).
CTRL
Control Display
6.
7.
8.
9.
3 -4
GAIN (proportional) display.
RATE (derivative) display.
RESET (integral) display.
HEATER CURRENT or HEATER POWER
Bar Graph in percent of full
scale.
Full Scale selection of HEATER
CURRENT or HEATER POWER for
four orders of magnitude.
Includes power OFF position.
Keyboard
11. Control Data input keys (Gain,
12.
13.
14.
15.
16.
17.
18.
19.
Rate, Reset, Setpoint, and
Manual Heater).
(Up) and
(Down) keys.
PROG (Programming),
(SCAN
and Sign), TIME, and POINT #
keys.
Decimal Keypad with Blue Legend
functions of SENSOR, CURVE#,
FILTER, MATH, UNITS, RSLTN
(ReSoLuTioN), DEV (DEViation),
CONTROL,
MAX (MAXimum), MIN
(MINinum),and MAXDEV (MAXimum
DEViation)
CLEAR and ENTER functions for
use with keypad 0, 1, 2, 3, 4,
5, 6, 7, 8 , 9, decimal point
and
minus sign.
Return-to-LOCAL key with annunciator.
REMOTE key with annunciator.
INT (INTernal Program) Key with
annunciator.
POWER ON-OFF switch
COPYRIGHT 3/88
Section III
M o d e l DRC-93C
3.7.4
Black Legend Keys
When one of the Black Legend keys
(GAIN, RATE, RESET, SETPOINT, MANUAL
HEATER, TIME, or POINT#) is pressed
it is not to be held down released
immediately.
The quantity described by the key
will begin to flash indicating that
it can be changed.
The keypad (0-9 and .) is then used
to enter the new value. Negative
quantities are preceded by the minus
key. The ENTER key completes
the operation and inserts the new
value.
The CLEAR key will cancel
the entry and return the instrument
to normal operation.
When the
(up) and
(down) keys
are used after selecting a Black
Legend key the
key will increment
and the
key decrement the quantity. Detailed operation of these keys
will be discussed in the sections
dealing with the specific Black
Legend functions.
SUMMARY: THE KEYPAD (0-9 AND .) ARE,
THE NUMBERS 0-9 AND DECIMAL
POINT WHEN A DISPLAY (SETPOINT,
GAIN, RATE, RESET, ORMANUALHEATER
ONLY
Units (K, C, F, V,
N)
A 5 digit display with sign
5. An indicator in the upper left
hand corner of the sign to
signal FILTER ON.
3.
4.
A Control arrow (CTRL) to the far
left of the TEMPERATURE block points
to the Controlling Sensor.
The Setpoint Display is discussed in
Section 3.10 with the CONTROL Block.
3.8.1
Sample
Inputs
and
Control
Sensor
The choice of which input is associated with the Control Sensor or the
Sample Sensor is determined by the
CONTROL key of the keypad and indicated by the CTRL annunciator arrow.
If the CTRL Arrow points up then the
Upper Display with its associated
SENSOR Number and UNITS are the
Control sensor. The Lower Display
is then the Sample Sensor with its
associated SENSOR number and UNITS.
Similarly, if the CTRL Arrow points
down then the Lower Display and its
associated SENSOR and UNITS is the
Control Sensor and the Upper Display
is the Sample Sensor.
3.8.2
U p p e r and Lower SENSOR Number
POWER) IS FLASHING
OTHERWISE THE
KEYS WILL CARRY OUT THE FUNCTION
DESCRIBED BY THE BLUE LEGEND. THE
ENTER AND CLEAR KEY ARE ONLY EFFECTIVE WHEN A QUANTITY IS FLASHING.
THE
KEY AND
KEY ARE USED IN
CONJUNCTION WITH BLUE LEGEND KEYS To
CHANGE THE QUANTITY BEING REQUESTED.
The selection of A or B inputs for
the Upper Display is changed by
holding in the SENSOR key and pressing the
(Up) key.
3.8 TEMPERATURE BLOCK
The A input is distinguished by a
uppercase letter A in the Sensor
window and the B input by a lowercase b in the Sensor window.
TEMPERATURE block consists of
Upper Display, Setpoint Display
the Lower Display. The Upper
Lower Displays each have
1. SENSOR Number
2.
(SCAN) indicator in the
upper left hand corner of the
SENSOR Number
The
the
and
and
COPYRIGHT 3/88
The selection of A or B inputs for
the Lower Display is changed by
holding in the SENSOR key and pressing the
(Down) Key.
While the SENSOR key is held down,
the Upper and Lower Displays will
show the card types being used by
the displayed sensor.
The GAIN,
RATE, and RESET windows are blank.
3-5
Section III
They are used to indicate REMOTE
POSITION DATA when an External Scanner (Models 8084 or 8085) are attached (see Section 3.9.2).
When the 8229 Scanner Conversion
Option is not present the display
toggles between the A and B input
cards.
3 . 8 . 3 8229
Scanner Input Option
With the addition of the Model 8229
Scanner Input Option, four more
inputs are added to the A channel
input. These additional inputs are
designated 1, 2, 3, and 4 in the
SENSOR window.
With the scanner conversion option
present, the SENSOR key and
(Up)
key increments the Upper Display
inputs in the sequence A-1-2-3-4-b-A
etc. Similarly for the Lower Display with the SENSOR key and
(Down) key.
The 8229 Scanner Input option is
covered in Section VII.
3.8.4 SCAN Function
The SCAN function allows the instrument to step between the two inputs
with a scan rate independently set
between 0 (Skip) and 99 seconds for
each input. Setting a dwell time to
zero automatically skips the channel
only when in the SCAN mode. If the
scanner option is present, inputs
(1-4) are included in the SCAN function and each has its own dwell time
which is set independently.
3.8.5 The SCAN Dwell Time
The dwell time for the Sensor inputs
associated with the Upper and Lower
Display can be displayed by pressing
the
key down for more than one
second. The display will read dt-00
for a dwell time of 0 seconds. If
it is desired to change the dwell
shown in the upper display, the user
continues to hold down the SCAN key
3-6
Model DRC-93C
and presses the
key. Both keys
can then be released. The dwell in
the Upper Display will flash indicating that it can be changed by
the keypad (0-9) and entered into
the instrument with the ENTER key.
Hitting the CLEAR key before the
ENTER key will cancel the entry and
return the instrument to normal
operation.
To change the dwell shown in the
Lower Display is the same except
keys are emthat the SCAN and
ployed.
When the dwell is being changed, in
addition to using the keypad (0-9)
there are two other methods to modify the dwell displayed. The first
method is to increment the dwell
with the
key and decrement it
with the
key. When the desired
dwell is displayed hitting the ENTER
key will store that dwell in the instrument and return to normal operation. The second method in which
the entry can be changed is by using
the keypad to enter an amount which
is to be added or subtracted from
the previous value. Hitting the
key will add the amount and the
key will subtract the amount. The
two methods can be used at will.
The ENTER key will enter the final
value into the instrument or the
CLEAR key will cancel the operation
at any time.
3 . 8 . 6 Upper and Lower D i s p l a y Units
3 . 8 . 6 . 1 U n i t s Select
The units of the Upper Display is
changed by holding down the UNITS
key and pressing the
(Up) key
until the units desired are obtainkey is pressed
ed. Each time the
the units of the Upper Display cycle
clockwise. The units which do not
pertain to the input card selected
are automatically skipped, i e. ,
only one of the sensor units (V,
or nF) is possible depending on
which sensor input card is present
.
COPYRIGHT 3/88
Model DRC-93C
within the instrument.
Similarly
the units of the Lower Display are
changed by holding down the UNITS
key and pressing the
(Down) key.
For any input card except the 9215,
the DRC-93C will read temperature
regardless of whether a curve is
stored within the instrument which
corresponds to the temperature sensor being interrogated. For diodes,
germanium, carbon glass, and all
other negative temperature dependence sensors; the default curve is
Curve 00 which is the D curve for
the DT-500-DRC sensors. For a positive temperature dependence temperature sensor such as platinum and
rhodium-iron, the default curve is
Curve 03 which is the standard 3750
DIN curve for platinum. This default will only occur if a curve of
opposite temperature dependence has
been inadvertently selected by the
user. In the case of the 9215 card,
temperature units are not allowed
due to the inability of this sensor
to hold a calibration upon cycling.
3.8.6.2
Sensor Units M o d e
3.8.6.2.1Voltage
Units
The voltage mode is allowed for the
9210-3 and -6 configurations, the
9220-3 and -6 configurations as well
as the older version 8210 and 8211
cards.
In the voltage mode, the
display has a resolution of 0.1 millivolt with the full scale range dependent on the input card (2.9999
volts for the -3 configurations and
the 8210 card and 6.5535 volts for
the -6 configurations and the 8211
input card). The actual Input Card
resolution is 0.05 millivolts and
0.1 millivolts, respectively. If a
voltage exceeding full scale is applied to the displayed input an
overload condition is present and is
indicated by OL on the display.
3.8.6.2.2
Resistance U n i t s
The Resistance mode is allowed for
COPYRIGHT 3/88
Section III
the 9317C, 9318C, and the 9220-P2,P3, and -R1 configurations as well
as the older 8219-P2, the 8219-P3
and 8219-R1 cards.
The display
range and resolution for the 9317C
is 0.000 to 9999.9 ohms; the 9318C
is 0.000 to 99999 ohms. Note that
the resistance automatically ranges
from
to --- -- to ---- - to
----- as the resistance increases in
value. If the input resistance exceeds the resistance range for the
card, an overload condition is
present and is indicated by OL on
the display.
--.---
.
The display ranges and resolutions
for the 9220-P2 (and 8219-P2), 9220P3 (and 8219-P3) and 9220-R1 (and
8219-R1) are 0.00 to 299.99 ohms,
0.0 to 2999.9 and 0.000 to 99.999
ohms respectively.
Again, if a
resistance exceeding full scale is
applied to the input,
OL
is
indicated on the display.
3.8.6.2.3
Capacitance Units
The capacitance mode is allowed for
the 9215 Input Card which can be
configured in the -15 or -150 configurations. The display range is
0.000 to 30.000 or 150.00 nanofarads, respectively. An input in
excess of the configured maximum is
indicated by OL on the display.
3.8.7
Display Resolution
The Model DRC-93C allows the user to
set his display resolution over the
range from 1 kelvin to 1 millikelvin
(0.1millikelvin for the 9317C input
card).
The temperature is rounded
to the least significant digit of
the resolution range selected.
Since the temperature display
resolution is dependent on both the
sensor units (voltage, resistance or
capacitance) resolution of the Input
Card as well as the sensor sensitivity, temperature resolution is greatly dependent on the sensor. Refer
to Table 3-1 for a representative
summary of “system” resolution,
3-7
Section III
(sensor plus instrument) versus sensor sensitivity.
3.8.7.1 Temperature Display Resolution Set
To examine the resolution of the
Upper and Lower Display hold in the
RSLTN key.
The displays will read
one of the following:
--- ., --- - ---.
I
--- --
I
-- ---
I
If it is desired to change the resolution then while holding down the
RSLTN key hit the
key to cycle
the resolution in the Upper Display
through those shown until the desired resolution is obtained. When
the keys are released the new resolution is entered in the DRC-93C.
Similarly, holding in the RSLTN key
and hitting the
key will change
the resolution in the Lower Display.
Changing the display resolution
fixes the resolution transmitted
over the computer interface as well
but does not change the resolution
of the “system”. Display resolution
can also be different for each input
card, i.e. , A and B.
Also note,
that the chosen resolution will only
be displayed when “appropriate”.
TABLE 3-1.
mv/K
0.1
1.0
10.0
100.0
In other words, only five digits can
be displayed.
In the temperature mode, the chosen
input is displayed in the selected
scale (K, "C o r °F) with a maximum
display capability of 0.01 degrees
above 100 kelvin, to 0.001 degrees
between 1 and 100 kelvin and in the
case of the 9317C resistance card to
0.0001 kelvin (0.1 millikelvin)
below 1 kelvin. Please note that
this is display capability and =ither system resolution nor necessarily accuracy of the reading. Also
note that if the sensitivity of the
sensor is too low to support this
resolution, i.e., one bit corresponds to greater than the above
resolution, some temperatures may be
skipped. This will be true for a
silicon diode sensor between 30
kelvin and 100 kelvin where the
sensitivity is approximately 2.5
millivolts per kelvin and the voltage resolution is 0.046 millivolts.
For this case, the resulting temperature resolution is 0.046/2.5 =
0.018 kelvin.
However, below 30
kelvin the silicon diode sensitivity
is approximately 25 millivolts per
kelvin which results in an approximate resolution of 0.002 kelvin
(0.046/25).
System Resolution V e r s u s Sensor Sensitivity
Sensor
Maximum Temperature
Sensitivity Resolution (in kelvin)
Voltage Mode
Model DRC-93C
9210/9220
-31
0.5
0.05
0.005
0.0005
-61
1.
0.1
0.01
0.001
Sensor
M a x i m u m Temperature
Sensitivity Resolution (in kelvin)
Resistance Mode
(1/R)
(dR/dT), K-1
0.001
0.01
0.1
1.
9317C/9318C
9220-P2,-P3,-R12
0.1
to 0.01
0.01
to 0.001
0.001 to 0.0001
0.0001to 0.00001
Note 1. The input resolution is 0.05 millivolts for the 9210/9220-3
and is 0.1 millivolts for the 9210/9220-6.
Note 2. This assumes an ability to resolve between 1 part in 104 and
1 part in 105 , where
=
[ (1/R)
(dR/dT)] and (
varies between 10-4 and 10-5
3-8
COPYRIGHT 3/88
Section III
Model DRC-93C
3 . 8 . 8 Filtering t h eA and B
Inputs
averaging algorithm within the
instrument is available which averages up to ten readings. This reading mode eliminates noise within the
cryogenic system analogous to averaging within a digital voltmeter.
This function can be examined and
selected or deselected by the FILTER
key and the
key and
key.
An
When the FILTER key is pressed, the
words On (filter on) and OFF (filter
off) are presented in the Upper and
Lower Displays. To toggle the filter of the input of the Sensor shown
in the upper display hold down the
FILTER key and press the
key.
Similarly holding the FILTER key and
pressing the
key toggles the
filter of the input of the Sensor
shown in the Lower Display from On
to OFF.
In operation, an indicator will
appear in the upper left hand corner
of the sign digit in the Upper
and/or Lower Displays to flag
“Filter-on” for that input.
If the averaging algorithm is used,
displayed temperature is the average
of between 1 and ten readings depending on the temperature variation. If an abrupt change in temperature is observed, averaging is
disabled and the last calculated
reading is displayed. As the disturbance is reduced in value, the
averaging gradually increases until
a total of ten readings are considered.
3.8.9 Math Functions
The DRC-93C has three built-in Math
Functions to retain the maximum and
minimum temperatures as well as the
maximum deviation from the setpoint
for the Sensor in the Upper Display
and the Sensor in the Lower Display.
The three keys MAX, MIN, and MAXDEV
on the keypad (digits 9, 6, and 3
COPYRIGHT 3/88
respectively) allow the user to
observe the MAXimum and MINimum
temperature, and MAXimum DEViation
from the Setpoint. When one of these
keys is depressed, the Upper and
Lower Displays will contain the selected Math Function.
These Math Functions are enabled
using the MATH key (decimal point on
the keypad) and the
key or
key. In combination with the MATH
key, the CLEAR key restarts the
process.
When the MATH key is depressed, the
Upper display shows “OFF” or “On”.
When “OFF” is displayed, the Math
Functions are inhibited. When “On”
is displayed, the Math Functions are
enabled. To change from “OFF” to
“On” and vice versa, hold the MATH
key down and hit the
key or
key to toggle between “On” and
“OFF”. When the MATH key is released, operation returns to normal.
If the “On” was left in the Upper
Display when the MATH key was released, then the instrument will
begin calculating the Math Functions.
If “OFF” was left in the Upper Display when the MATH key was released,
then the instrument freezes the
contents of the Math Functions. The
MAX, MIN, and MAXDEV keys can be
used to observe the last readings of
the Math Functions.
If it is desired to restart the
calculation of the Math Functions,
the MATH key is held down and the
CLEAR key hit, the Lower Display
will show the word “CLEAr” to indicate that the registers holding the
Maximum, Minimum and Maximum Deviation have been zeroed. If the Math
Functions were enabled (”On”)then
new Math Functions will be computed.
Once the Math Functions have been
cleared and enabled ( “On”), changing
the Sample or Control units will
result in inconsistant values being
stored in the Math Function regis3-9
Section III
Model DRC-93C
ters. The new Math Functions can be
observed at any time by depressing
and holding in the appropriate key
(MAX, MIN, or MAXDEV).
3.9.1.2
Number
Display of Accessed Curve
3.9.1 Standard and Precision Option
To determine which curve is being
used press and hold the CURVE# key.
The displays will show the letters
“CU” for Curve Number followed by a
curve number in each display.
The standard curves are given in
The Precision Option
Table 3-2.
Curves are given in Table 3-3.
Table 3-3. Sensor Curve Table
Information - Precision Option Table
Table 3-2. Standard Curve Information
Curve #Lines Address Description
3.9 SENSOR CURVE SELECTION
curves
Curve
No.
00
01
02
03
04
05
Temperature
Range (K)
1
1
1
14
1
-
324.9
324.9
324.9
799.9
474.9
Description
DRC-D
DRC-E1
CRV 10
DIN-PT
CRV 10
RESVRD
3.9.1.1 The Precision Option
For Lake Shore stored Precision
Option, a proprietary algorithm is
used to fit the calibration data to
within a few millikelvin over the
entire temperature range.
The Precision Option Table shown in
Table 3-3 gives the standard curves
as well as any Precision options
which are factory installed including their address and the number of
data points associated with each
curve. This Table should be updated
for the instrument if additional
curves are added at a later time.
Up to 25 Precision Option Curves can
be stored in the DRC-93C with an
average of 31 lines per curve. A
Precision option Curve can have up
to 97 points with two additional end
points automatically put into the
curve table by the DRC-93C software.
3-10
00
01
02
03
04
31
31
31
31
31
1D40
1EA0
1F50
2000
CRV 10
05
06
07
08
09
31
20B0
RESVRD
1DFO
DRC-D
DRC-E1
CRV 10
DIN-PT
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
COPYRIGHT 3/88
section III
M o d e l DRC-93C
For Example, by holding down the
CURVE# key the Displays might look
as follows:
SENSOR
Upper Display
Lower Display
A
b
DISPLAY
CU-02
CU-06
The CU-02 in the Upper Display indicates that the Sensor using the
Upper Display is calculating the
temperature with the data of Curve
#02.
Curve #02 from Table 3-2 is
the CRV 10 for the DT-470 Series
Sensors.
The CU-06 in the Lower
display indicates that the Precision
Option is installed and the DRC-93C
is calculating the temperature with
the data stored in Curve #6.
Since the DRC-93C knows which type
of input card is present for each
input (assuming that two input cards
were installed), it will not, for
example, allow the selection of the
platinum curve (Curve #03) for a
diode input card. If Curve #03 is
selected, the DRC-93C will default
to the lowest curve number with the
correct temperature coefficient, in
this case, curve #00. For the case
of a platinum input card and no
Precision Option curves present, the
DRC-93C will select Curve #03,
regardless of the curve selected
using the CURVE# key.
3.9.1.3
Option
Addition of 8229 Scanner
Adding the 8229 Scanner to Input A
adds four more Inputs 1, 2, 3, and
4. Each of these inputs has its own
curve assigned using the CURVE# key.
Changing the Curve used by
3.9.1.4
a Sensor (No External Scanners)
With the CURVE# key held in, pressing the
(up) key allow the user
to change the curve # used by the
Upper Display Sensor.
When the
CURVE# key is let up, the instrument
will return to normal operation with
COPYRIGHT 3/88
the new curve being selected for
calculation by the Sensor associated
with the Upper Display. Similarly,
the CURVE:# key and the
(down) key
change the curve # for the sensor
associated with the Lower Display.
3.9.2
External S c a n n e r Model 8085
Up to three 8085 Scanners can be
daisy-chained together to give 30
remote positions for either the A
input or the B input of the DRC-93C.
In order for the instrument to select the correct curve for the sensors connected to an 8084 or 8085
Scanner it is necessary for the user
to make a connection between the
REMOTE POSITION DATA Connector of
the Scanner to the DRC-93C REMOTE
SENSOR ID Connector.
In this way
the DRC-93C will have the data regarding which position the scanner
is in and thus which external sensor
is being examined. The data on the
REMOTE SENSOR ID Connector will be
called the REMOTE POSITION DATA.
The user must provide the DRC-93C
the information which relates the
REMOTE POSITION DATA to the Curve
Number. This information is stored
within the DRC-93C in its Correlation Table (See Table 3-4).
In addition, the user must enable
the DRC-93C to use the REMOTE POSITION DATA. This is done by using
the CURVE#, REM,
and
keys as
described in the next section.
3.9.2.1
Selection
POSITION DATA
of the REMOTE
To allow the REMOTE POSITION DATA to
determine the curve selection, the
user does the following:
1. Press the CURVE# key and hold it
down.
The Curve # associated
with the Upper and Lower Displays
will be given and the GAIN, RATE,
and RESET blanked.
3-11
Section III
M o d e l DRC-93C
2. While holding in the CURVE# key,
A1, A2, A3, and A4 all use the Curve
Number from the A column of the
correlation table.
Now press the
(Up) key to toggle the Upper Display External
curve selection.
The REMOTE
POSITION DATA will appear in the
GAIN windows to indicate that the
REMOTE POSITION DATA will be used
for curve selection by the Upper
Display Sensor. Hitting the
key again will blank the GAIN
window indicating that the REMOTE
POSITION DATA will not be used.
The operation is the same for the
key except that the Lower
Display Sensor and RESET window
are involved.
3.9.2.3
Modifying the Correlation
T a b l e from the Front Panel
press the REM (REMote)key.
Release the CURVE# key.
3.
4. When the desired
condition is
reached, release all keys.
3.9.2.2
The Correlation T a b l e
The CURVE# key will show that the
External Scanner has been selected
by indicating the REMOTE POSITION
DATA in the GAIN window for the
Upper and in the RESET window for
the Lower Display. The instrument
uses the REMOTE POSITION DATA (the
signal applied to the REMOTE SENSOR
ID Connector from the Scanner) in
conjunction with the Correlation
Table of Table 3-4 to obtain the
Curve Number.
If the REMOTE POSITION DATA is zero,
then instrument uses the same Curve
Number assigned to the input without
the Scanner. When there is an 8229
Scanner option present, there are 5
Curve Number assignments for Input
A--- one each for AO, A1, A2, A3, and
A4.
The DRC-93C is shipped from the
factory with curve 02 stored in all
positions of the Correlation Table.
The Correlation Table is modified by
using the CURVE# and
key and
key as follows.
1. Use the procedure described in
the previous section to put the
instrument in the External Scanner mode.
2. Apply a signal on the REMOTE SEN-
SOR ID Connector to indicate a
position number, the REMOTE
POSITION DATA. This can be done
by attaching a Scanner and selecting a position.
3. Select the Curve Number desired
for that position from the front
panel as described in section
3.9.1.4.
The GAIN or RESET window must have the REMOTE POSITION
DATA to show that the function is
enabled.
4. When the ENTER key is pressed,
the Curve Number will be stored
in the Correlation Table in the
Position indicated by the REMOTE
POSITION DATA in the GAIN window
if the Curve in the Upper Display
was altered or in the RESET window if the Curve# in the Lower
Display was altered.
If the REMOTE POSITION DATA is nonzero, then the Curve Number is
selected from the row of the Correlation Table corresponding to the
value of the REMOTE POSITION DATA.
When there is an 8229 Scanner Option
present, there is only one Curve
Number assignment for Input A---A0 ,
3-12
COPYRIGHT 3/88
Model DRC-93C
3-4.
Correlation T a b l e for
Curve # from REMOTE POSITION DATA
Table
REMOTE
POSITION
DATA
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
3.9.3
Curve#
for
Input A
A01
A02
A03
A04
A05
A06
A07
A08
A09
A0A
A0B
A0C
A0D
A0E
A0F
A10
All
A12
A13
A14
A15
A16
A17
A18
A19
AlA
A1B
A1C
A1D
A1E
A1F ERR09
Curve#
for
Input B
BO1
BO2
BO3
BO4
BO5
BO6
BO7
BO8
BO9
BOA
BOB
B0C
BOD
B0E
B0F
B10
B11
B12
B13
B14
B15
B16
B17
B18
B19
BlA
B1B
B1C
B1D
B1E
B1F ERR09
Programming Curves from the
Front Panel
This section describes how the user
can enter his own sensor calibration
via the front panel.
Section IV
covers entry over the IEEE-488 or
RS-232C interfaces.
The curve is
stored in a battery back-up nonvolatile RAM (NOVRAM) which can be
read and written an unlimited number
of times. The number of data points
stored per curve can be between 2
and 99; two being the lower limit
which defines a straight line.
COPYRIGHT 3/88
Section III
3.9.3.1 Accessing Stored Curve D a t a
In order to access stored curve data
hit the PROG (Programming) key. The
PROG indicator will turn on and
flash.
Next hit the CURVE# key.
The PROG indicator will stop flashing and turn on.
The Upper and
Lower Displays will blank and the
Setpoint Display will contain 00-00
with the second zero from the left
flashing. The Upper Display UNITS
will show K for kelvin and the Lower
Display UNITS V for volts.
NOTE: At any time, if it is desired
to exit from the Curve Programming
routine hit the PROG key. Operation
will return to normal. The CLEAR
key is used to clear a number partially entered but not desired.
IF A KEY IS NOT HIT FOR A PERIOD OF
20 SECONDS,
THE INSTRUMENT WILL
ABORTTHECURVEPROGRAMMINGRUTINE
AND RETURN TO NORMAL OPERATION
The flashing quantity in the Setpoint Display is the Curve # to be
examined.
The other quantity is
used to hold the number of points in
the Curve Data of the selected
Curve.
Using the keypad (0-9) type in the
Curve# to be examined followed by
the ENTER key. The CLEAR key may be
used if there is an error in typing
the curve #. Also the keypad can be
used until the correct Curve # is
displayed. For example if 30 shows
in the display and the 2 key is hit,
the 3 of the 30 will disappear and
the 2 show up in the units digit to
give 02. Hitting the ENTER key will
cause the instrument to accept the
entry and to search for Curve #02.
Since Curve #02 is present (it is a
Standard Curve--see Table 3-2), the
instrument will find the curve and
then show
3-13
Section III
Model DRC-93C
0.0
02-31
6.5536
in the displays. The 02 in the Setpoint Display is the Curve# and the
31 indicates that there are 31 lines
(or points) in the curve data.
Points are numbered from 1 to the
total number of points---here 31.
The 0.0 in the Upper Display is the
temperature in kelvin for point #31
and the 6.5536 the sensor voltage of
point #31 (at 0.0 K).
A Standard Curve cannot be
edited, but the standard curve data
can be examined.
NOTE:
To examine Point#12 first hit the
POINT# key. The Point# in the Setpoint Display will begin to flash.
Enter 12 using the keypad followed
by the ENTER key. The displays will
read
115.0
02-12
0.9445
to indicate that Point# 12 of
Cuwe#02 is 0.9445 volt at 115.0 K.
At any time that the POINT# key is
appropriate, the A key and key can
be used to examine the next higher
numbered point and lower numbered
point respectively.
If the
key
was pressed after point# 12 was
displayed in the example given
above, the display would change to
95.0
02-13
0.9857
The A key and
key do not operate
when the instrument is requesting a
curve#, temperature, or voltage.
To exit the Curve Programming
routine hit the PROG key.
3-14
3.9.3.2
Entering New Curves
The user should know what Curve# is
available for new data by keeping
accurate records and updating Table
3-3 as curves are added.
If an
error is made in record keeping, the
instrument will catch it since 00
number of points indicates an available set of data storage.
It is suggested that the curve data
be put in ascending Raw Units order
prior to the curve entry session.
The data must be in ascending units
order. The temperature will follow
the temperature coefficient of the
curve being entered. The temperature will be in decreasing order for
a negative temperature coefficient
curve and increasing for a positive
temperature coefficient curve.
Let us say that we wish to enter a
new set of curve data into an available slot at Curve#21. From normal
operation, the user presses the PROG
key followed by the CURVE# key to
enter the Curve Programming routine.
Pressing the 2, 1 and ENTER keys
tell the instrument to find Curve#21
and will indicate that it is available by showing 00 number of points.
The displays will read as follows:
-----
21-00
-----
The dashes indicate there is no data
present for curve number 21.
No
entries will flash. At this time,
one of four keys can be selected;
PROG, CURVE#, or POINT#.
The PROG key will abort the curve
programming and return the instrument to normal operation.
Pressing the CURVE# key will cause
the Curve# portion of the Setpoint
Display to flash allowing the user
to select another curve.
COPYRIGHT 3/88
M o d e l DRC-93C
Pressing the POINT# key will cause
the point # entry in the Setpoint
Display to begin flashing and the
Upper and Lower displays to be
cleared. The keypad (0-9) is used
to enter a point# to be inserted.
Type 01 and press the ENTER key.
Now the Upper and Lower displays
will go to 0.0 and the Upper display
will begin flashing. Use the keypad
to enter the temperature of the
point in kelvin. The decimal point
can be used, but the resolution will
be limited to --- If the entry
is begun but not as desired, the
CLEAR key can be used to clear the
display to restart.
. .
The first and last points entered
are determined by the temperature
coefficient of the curve being entered. For a negative temperature
coefficient (N) curve the first
data point (#01) is 499.9K and
0.0000 volts. For a positive temperature coefficient (P) curve the
first data point is 0.0K and 0.0000
volts.
The quantity is accepted for the
temperature when the ENTER key is
pressed.
You cannot use the
key or
key when entering curve data. Only
the keypad (0-9,and .) and the CLEAR
key are active.
NOTE:
After the temperature is entered,
the Lower Display will begin to
flash. The keypad is used to enter
the Raw Units Data for the point as
described in Table 4-14. The entry
is accepted when the ENTER key is
pressed.
Another point can be added by pressing the POINT# key. After the curve
has been entered, the last data
point to enter is 0.0K and 6.5536
volts for N type and 999.9K and
6.5536 volts for P type curves.
COPYRIGHT 3/88
Section III
F a i l u r e to enter the correct
end points w i l l result in
unpredictable results.
NOTE:
curve
Pressing the PROG key will return
operation to normal with the curve
being entered into the memory of the
instrument and available through an
assignment as described in section
3.9.1.
3.9.3.3
Editing Existing Curve D a t a
Curve data can be modified using the
same procedure described in the
previous section. The difference is
that the temperature and voltage
(raw data) will be shown in the
Upper and Lower displays respectively after the POINT# has been selected. If it is not desired to edit
the point, then simply enter another
point# using the POINT# key or press
the PROG key to return to normal
operation.
Following the editing of a data
point, the unit compares the temperature and voltage entered against
the existing curve to see if either
match and existing point. The point
is matched first in temperature,
then voltage.
If a match occurs,
the point is edited to reflect the
change.
If no match occurs, the
unit inserts the new point into the
curve in the correct increasing Raw
Units order.
3.9.3.4
Summary
of Curve Programming
from the Front Panel
1. The Curve Programming routine is
entered by pressing the PROG key
followed by the CURVE# key. The
PROG light will remain on while
in the routine and turnoff when
operation returns to normal.
2. The displays have the following
format during curve programming.
Upper Display:
Temperature in K
Setpoint Display: Curve# - Point#
Lower Display:
Raw Units Data
3-15
Section III
3.
The Upper and Lower SENSOR windows are blank. The Upper UNITS
show “K” and the Lower UNITS “V”
to indicate Raw Units Data (see
Table 4-19).
Model DRC-93C
The operation is completed with
the ENTER key or cancelled with
the CLEAR key.
2. Increment the quantity using the
key or decrement the quantity
with the
key. The operation
is completed with the ENTER key
or cancelled with the CLEAR key.
4. When no digits are flashing, the
Curve#
is accessed using the
key and the POINT# by the
POINT# key.
CURVE#
5.
The keypad (0-9) is used to enter
a quantity after it begins to
flash. The decimal point can be
used with Temperature or Raw
Units Data but not with Curve# or
Point#.
6. The
PROG key always returns
operation to normal operation.
7. The CLEAR key clears the display
if pressed after an entry is
begun.
8.
The instrument will return to
normal operation if no key is
pressed for 20 seconds.
3.
The quantity can be incremented
or decremented by any amount as
follows. Enter the digits of the
increment or decrement desired
via the keyboard.
The decimal
point can be entered as desired.
Pressing the
key will add the
quantity and the
key will
subtract the quantity. The operation is completed with the ENTER
key or cancelled with the CLEAR
key.
Methods 2 and 3 can be used together
in any combination. This same procedure is also used to enter the
dwell except that the minus sign and
decimal point are not permitted.
(See section 3.8.5).
3.10 SETPOINT and CONTROL BLOCK
3.10-1 SETPOINT
Parameters entered using a blue key
with a black legend (SETPOINT, GAIN,
RATE, RESET, and MANUAL HEATER)
require the use of the ENTER key.
When one of these keys is pressed
and released, the least significant
digit or digits will flash to indicate that the parameter can be entered. The quantity can be entered
in three ways.
To change the Setpoint, press the
SETPOINT key an then use methods 1,
2, and/or 3 described above.
IN ALL CASES, pressing the
CLEAR key will result in the old
value being inserted and the operation completed. Pressing the ENTER
key enters the quantity in the appropriate display into the DRC-93C.
NOTE:
1. Enter the digits via the key-
minus sign can be
board. The
used with the Setpoint and must
preced the digits. The decimal
point can be entered as desired.
3-16
If in degrees Celsius or degrees
fahrenheit, the (-) key can be used
to change the sign of the setpoint.
3.10-2 GAIN
Variable gain (proportional) allows
adjustment of overall controller
gain over a range from 0.1to 99.
To change the Gain, press the GAIN
key and use methods 1, 2, and/or 3
described above.
3.10-3 RATE
Adjusts rate time constant of differentiator. Effectively sets time
constant between 1 and 990 seconds.
COPYRIGHT 3/88
Model DRC-93C
These are displayed as 0.1 to 99
which means that the displayed number is multiplied by ten to get the
rate in seconds. For a discussion
of beats per second and time constants, see the Application Note
enclosed as an Appendix to this
manual.
To change the Rate, press the RATE
key and use methods 1, 2, and/or 3
described above.
3.10.4 RESET
Adjusts reset (integral) time constant of integrator.
Effectively
sets time constant between 1 second
and 990 seconds.
These are displayed as 0.1to 99.
To change the RESET, press the RESET
key and use methods 1, 2, and/or 3
described above.
3.10.5
MANUAL HEATER POWER
The DRC-93C provides a feature in
which the heater power can be set
manually. The Manual Heater Power
value is indicated on the Bar Graph
by a blinking segment at the percent
at which it is set.
To change the Manual Heater Power,
press the MANUAL HEATER key and use
methods 1, 2, and/or 3 described
above. If the decimal number 5 is
entered, the Bar Graph will blink
the segment at 5%. If a zero is
entered immediately after the 5
(thus entering 50) the Bar Graph
will blink the segment at 50%. The
CLEAR key cancels anything entered
and returns the instrument to normal
operation.
The ENTER key inserts
the new Manual Heater Power and then
returns to normal operation.
COPYRIGHT 3/88
3.11 HEATER POWER
3.11.1
Section III
HEATER %.
The Bar Graph displays the magnitude
of the heater power in percent of
full scale. Full scale is defined
as the product of the maximum heater
current of one ampere squared times
the heater resistance times the
range setting. The DRC-93C Temperature Controller is shipped from the
factory with the Bar Graph indicating power. If the user prefers, he
can change this to a current reading
by turning on switch 1 of the eight
station dip switch located at the
rear center of the main board.
3.11.2
The HEATER POWER RANGE
The heater power range setting is
determined by the keys directly
below the HEATER POWER Bar Graph.
MAX corresponds to a 100 or 1 multiplier, while -1, -2, -3 and
-4 corresponds to a 10-1 10-2 10-3
and 10-4 multiplier respectively.
The OFF key turns off the output
power independent of the setpoint
and the control parameters.
NOTE: The DRC-93C is equipped with
a current limit vernier on the rear
panel which can limit the output
current on the MAX scale between
0.33 and 1 ampere, dependent on
setting. If the instrument will not
deliver full power, this vernier may
be set wrong or the load resistance
may be too large and the unit is
compliance voltage limited.
NOTE:
If a SETPOINT, GAIN, RATE,
RESET, MANUAL HEATER POWER or HEATER
POWER RANGE is entered too quickly,
the Unit may not update the parameter properly.
The instrument
Display and MAIN Boards verify
entered parameters each update
cycle.
changing a parameter more
than once in an update cycle may
result in inconsistant parameters
being entered.
3 -17
Section III
Model DRC-93C
DRc-93C Temperature controller
Rear Panel
Figure 3-2.
Figure 3-2.
Model DRC-93C Temperature Controller
Rear Panel Description
1.
Line cord receptacle with fuse and voltage selection
2.
Sensor INPUT A connector (J1)
3.
Sensor I N P U T B connector (J2)
4.
HEATER RESISTANCE selector switch
5.
Monitors output of Sensor INPUT A and Sensor INPUT B buffered voltages
and 8225 linear analog output option (J3)
6.
REMOTE SENSOR ID (J5)
Models 8084 or 8085
7.
IEEE-488 address switch
8.
IEEE-488 connector (J4)
9.
Heater Power output terminals (J6, J7, J8)
- Connects to POSITION DATA of
Scanner (optional)
10. Optional interface access plate (J9) (8229 Scanner Option)
11. optional interface access plate (J10) (8223 RS-232C Option)
12. MAX HEATER POWER Limit
13. Optional connector access plate (J11)
3-18
COPYRIGHT 3/88
M o d e l DRC-93C
3.12
LOCAL/REMOTE BLOCK
3.12.1
3.14 HEATER CURRENT LIMIT
LOCAL.
The DRC-93C Temperature Controller
has a current drive output with a
maximum current rating of one ampere
unless the optional 1.5 ampere output (W60) was ordered, or the current-limiting vernier has been set
at a lower value.
The LOCAL key is used to return the
instrument from remote control by
the IEEE-488 BUS or the RS-232C optional interface to front-panel control.
3.12.2
The REMOTE key is used to place the
controller under remote control and
to disable the front panel. When
the REMOTE key is pressed for more
than one second, the display shows
the IEEE-488 address of the instrument.
with the current-limiting vernier on
the back of the instrument, the output current on the MAX scale can be
limited anywhere between 1 ampere
and the maximum current for the
10-1 scale (330 mA).
This allows
the user to limit the maximum power
to between 50 watts and 5 watts,
dependent on his requirements.
3.13 REMOTE SENSOR ID
Table 3-5. Pin Assignments for the
J5 REMOTE SENSOR ID Connector
REMOTE
REAR PANEL DESCRIPTION
The REMOTE SENSOR ID connector is
connected to
the REMOTE POSITION
DATA output of a Model 8084 or Model
8085 Sensor Scanner or a Model
SW-10A ten-position switch. This
input is called the REMOTE POSITION
DATA and allows the user to
automatically call up different curves for different sensor/channel
positions when the instrument is
used with either remote switch (see
The Parallel input
Section 3.9.2).
data format is given in Table 3-5.
The user may supply to the REMOTE
SENSOR ID his own parallel BCD 5
volt signal referred to the DIGITAL
GROUND on pin 12.
COPYRIGHT 3/88
J5 CONNECTOR Pin Assignments
151311
9 7 5
16 14 12 10
8
6
3
4
1
2
ONLY BOLD PINS USED
J5
1
2
4
6
8
10
12
14
16
Function
+5
RESERVED
Bit 3
Bit 2
Bit 1
Bit 0 (LSB)
DIGITAL GROUND
Bit 4 (MSB)
RESERVED
3-19
S E C T I O N
R E M O T E
4-1.
O P E R A T I O N
IEE-488 INTERFACE
The IEEE-488 INTERFACE is an instrumentation bus with hardware and
programming standards designed to
simplify instrument interfacing.
The IEEE-488 INTERFACE of the DRC93C fully complies with the
IEEE-488-1978 standard and incorporates the functional, electrical
and mechanical specifications of
the standard. It also follows the
supplement to that standard titled
“Code and Format Conventions for
use with IEEE Standard 488-1978”.
This section contains general bus
information, ModelDRC-93C interface
capabilities, addressing and the
programming instructions that
control the DRC-93C functions.
IEE SPECIFICATIONS
AND OPERATION
4 - 2 GENERAL
The following discussion covers the
general operation of the IEEE-488
interface. For a more detailed
description of signal level and
interaction, refer to the IEEE
Standard 488-1978 publication "IEEE
Standard Digital Interface for
Programmable Instrumentation”.
All instruments on the interface
bus must be able to perform one or
more of the interface functions of
TALKER, LISTENER, or BUS CONTROLLER.
A TALKER transmits data onto the
bus to other devices. A LISTENER
receives data from other devices
through the bus. TheBUS CONTROLLER
designates to the devices on the
bus which function to perform.
The DRC-93C performs the functions
of TALKER and LISTENER but cannot
be a BUS CONTROLLER.
The BUS
CONTROLLER is your Digital Computer
which tells the DRC-93C which
COPYRIGHT 3/88 LSCI
I V
functions to perform.
The interface works on a party line
basis with all devices on the bus
connected in parallel. All the
active circuitry of the bus is
containedwithin the individualdevices
with the cable connecting all the
devices in parallel to allow the
transfer of data between all devices
on the bus.
The following discussion of the
signal lines on the bus are for
general information. Your digital
computer handles these lines through
its circuitry and software. Theuser
need never concern himself with
these lines or signals, however,
knowledge of their purpose will
help one to understand the operation
of the Interface.
There are 16 signal lines contained
on the bus:
1.
2.
3.
8 Data Lines
3 Transfer Control Lines
5 General Interface Management
Lines
The data lines consist of 8 signal
lines that carry data in a bit
parallel, byte serial format.
Theselinescarryuniversalcommands,
addresses, programdata, measurement
data and status to all the devices
on the bus.
The three Transfer Control lines
and the five Interface Management
lines are asserted low which means
that they carry out their function
when pulled low. When the voltage
on one of these lines is high then
the line is not asserted and the
function is inhibited. The General
Interface Management Lines IFC
(Interface Clear), ATN (Attention),
4-1
Section IV
.
Model DRC-93C
REN (Remote Enable), EOI (End or
Identify) and the SRQ (Service
request) manage the bus and control
the orderly flow of commands on the
bus. The IFC, ATN, and REN management lines are issued only by the
BUS CONTROLLER.
cepted) Signalsontheselines operate
in an interlocking hand-shake
mode. The two signal lines, NRFD
and NDAC, are each connected in a
logicalAND to all devicesconnected to
the bus.
The IFC (InterfaceClear) management
line is pulled low by the BUS
CONTROLLER to clear the interface.
after it places its data on the
DATAlines. ThistellstheLISTENERS
that information on the DATA lines
is valid.
A LISTENER holds the
NRFD line low to indicate it is not
ready. Sincethese lines are connected
in a logical AND to all other
devices, then the NRFD line will
not go high until all of the devices
are ready.
The ATN (Attention) line is the
management line used by the BUS
CONTROLLER to get the attention of
the devices on the bus. The BUS
CONTROLLER does this by pulling the
ATN line low and sending talk or
listen addresses on the DATA lines.
When the ATN line is low, all
devices listen to the DATA lines.
When the ATN line goes high, then
the devices addressed to send or
receive data (for example, the DRC93C) perform their functions while
all others ignore the DATA lines.
The REN (Remote Enable) management
line is pulled low by the BUS
CONTROLLER to enable a device (the
DRC-93C) to perform the functions
of TALKER or LISTENER.
TheDAVlineispulledlowbytheTALKER
The NDAC line is pulled low by a
LISTENER while it is receiving the
DATA and lets it go high when the
DATA is captured. Since the NDAC
lines of all devices are connected
in a logical AND, the NDAC line
will not go high until all devices
have received the DATA.
4.3
INTERFACE CAPABILITIES
The IEEE-488 Interface capabilities
of the Model DRC-93C are listed
in Table 4-1 as well as in mnemonic
format on the instrument's rear
panel.
The EOI (End or Identify) management
line is pulled low by the BUS
CONTROLLER or a TALKER (theDRC-93C)
T a b l e 4-1. Interface Functions.
to indicate the end of a multiple
byte transfer sequence. Also the
EOI line along with the ATN line Mnemonic Interface Function Name
are pulled low by the BUS CONTROLLER
SH1 Source Handshake Capability
to execute a polling sequence.
AH1 Acceptor Handshake Capability
The SRQ (ServiceRequest) management T5 Basic TALKER, serial poll capability, Talk only,Unaddressed
line is pulled low by a device (for
to Talk if addressed to Listen
example, the DRC-93C) to signal the
Basic LISTENER, Unaddressed to
BUS CONTROLLER that a process is L4
Listen if addressed to Talk
completed, a limit, overload or
error encountered. In some cases SR1 Service Request capability
this means that service is required. RL1 Complete Remote/Local capablty
PPO No Parallel Poll capability
Transfer of the information on the DC1 Full Device Clear capability
data lines is accomplished through D T O No Device Trigger capability
the use of the three signal lines: co No System Controller capablty
DAV (Data Valid), NRFD (Not Ready El Open Collector Electronics
for Data) and NDAC (Not Data Ac4-2
COPYRIGHT 3/88 LSCI
Model DRC-93C
Section IV
4.4 DRC-93C IEEE-488 ADDRESS SWITCH
The IEEE-488 Address Switch is
located on the instrument's rear
panel (see Figure 3-2, Key No. 7).
Refer to Figure 4-1 for the following
discussion.
4.4.1
.
Terminatingcharacters
(delimiters)
Switch 1 (*) is used to define the
instrument's terminating characters
(delimiters). The OPEN (0)position
selects the ASCII characters CR and
LF (Carriage Return and Line Feed)
as the terminating characters for
input and output data.
For the
output data from the DRC-93C back
to the computer over the Bus, the
EOI line is set by the DRC-93C with
the output of the Line Feed (LF)
This setting (0) for switch 1 is the
setting for all Hewlett-Packard
computers.
.
F i g u r e 4-1,
When Switch 1 (*) is CLOSED (1), a
variableterminating characterformat
may be selected for the input and
output data. In this configuration
the power-up (default) terminating
characters are LF and CR with the
EOI line being set with the output
of the Carriage Return (CR) However, the two terminating characters
can be changed via input data to
the DRC-93C as detailed in Table
4-6. If the terminating characters
are changed by the user, these are
only in effect until the instrument
is turned off.
.
4.4.2
TALKER and/or LISTENER Configuration
Since the DRC-93C is both a TALKER
and a LISTENER, normally switches
two and three should both be OPEN
(0). These switches are usually of
use when one instrument is a TALKER
and another instrument is a LISTENER
and they are to share the same
address.
IEEX-488 Address Switch for the DRC-93C
*
D
T
D
L
168
4
2
1
1
2
3
4
6
7
8
5
OPEN
CLOSED (1)
OPEN (0)
Address switches: 4 is MSB(16) ;
8 is LSB(1)
Switch 3: CLOSED (1) position sets the 93C in the
"talk-only" mode by disabling LISTENER capability.
Switch 2: CLOSED (1) position sets the 93C in the
“listen-only” mode by disabling TALKER capability.
Switch 1: used to define the instrument's delimiters.
Refer to Section 4.4.1 of the text for details.
COPYRIGHT 3/88 LSCI
4-3
Section IV
M o d e l DRC-93C
Table 4-2.
Allowable Address Codes for the DRC-93C
(Factory preset address is decimal 12)
ASCII Code
character
Listen
SP
!
“
#
$
%
&
I
(
)
*
+
-
‘
0
1
2
3
4
5
6
7
8
9
,
<
=
=
>
*
4-4
Bit
2* 3
A d d r e s s switches
4
5
6
7
8
5-bit
Decimal code
Talk
B7 B6
B 5B 4B 3B 2B 1
@
A
B
C
D
E
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
1
1
0
0
0
1
0
1
0
1
02
03
04
05
F
H
I
J
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
1
1
0
0
1
0
1
0
1
0
06
07
08
09
10
K
L
M
N
O
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
1
1
1
1
1
0
0
1
1
1
0
1
0
1
11
12
13
14
15
P
R
S
T
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
0
0
0
0
0
0
1
0
0
1
1
0
0
1
0
1
0
16
17
18
19
20
U
V
W
X
Y
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
0
0
1
1
1
1
1
0
0
0
1
1
0
0
1
0
1
0
1
21
22
23
24
25
Z
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
0
0
1
1
1
1
1
0
0
1
0
1
0
1
0
26
27
28
29
30
G
Q
[
\
1
Only the first five b i t s of the binary code are
listed. These b i t s are the same for the TALK
and LISTEN address. The sixth and seventh b i t s
(BUS CONTROLLER originated) determine whether the
instrument is being addressed to TALK or LISTEN
00
01
Factory
preset
address
Function
Bit
2 3
TALK
LISTEN
1 0
0 1
COPYRIGHT 3/88 LSCI
Model DRC-93C
4.4.3
The IEEE-488 INTERFACE bus
address for the DRC-93C is set by
switches 4 through 8 which are
reserved for the address selection.
Switch 4 is the most significant bit
(MSB[=16]) and 8 is the least significant bit (LSB[=1]).
The factory preset address of this
instrument is 12 (see Table 4-2).
Address switch numbers 5 and 6
should be CLOSED (1) which will
result in the Address Switch having
a setting of 00001100 or 10001100
dependent on the requirements for
the delimiters.
4.5 IEEE-488 BUS COMMANDS
4.5.1
The Uniline Command
A Uniline Command (Message) is a
command which results in a single
signal line being asserted. The
DRC-93C recognizes two of these
messages from the BUS CONTROLLER,
REN and IFC (See Table 4-3). When
the BUS CONTROLLER executes the appropriate software code the effect
is to pull the corresponding Interface Management line low.
For
example, when the software command
REMOTE712 is executed by the HP86
digital computer, the management
line REN is pulled low and the listen
address 12 issued to signal the
instrument having address 12 (DRC93C) to go into the remote mode.
The SRQ is a uniline command asserted
by the DRC-93C when it wishes to
signal the BUS CONTROLLER. The BUS
CONTROLLER will in turn use the
Addressed command SPE (Serial Poll
Enable) described below to interrogate the DRC-93C about the reason
or reasons for the communication.
4.5.2
The Universal Commands
The Universal Commands shown in
Table 4-3 are those multiline
commands that address all devices
on the bus.
A multiline command
involves a group of signal lines.
COPYRIGHT 3/88 LSCI
Section IV
All devices equipped to implement
such commands will do so simul-
taneously when the command is
transmitted. As with all multiline
commands, these commands are transmitted with ATN line asserted
(low).
There are two Universal
commands recognized by the DRC-93C,
Local Lockout and Device Clear.
(Local Lockout) - LLQ is sent to
instruments to lock out (preventthe
use of) their front panel controls.
LLQ
DCL (Device CLear) - DCL is used to
return the DRC-93C to the power-up
conditions.
4.5.3
The Addressed commands
The Addressed Commands shown in
Table 4-3 are multiline commands
that must include the DRC-93C
listen address before it will
respond to the command in question.
Note that only the addressed device
will respond to these commands.
The DRC-93C recognizes three of the
Addressed commands; SDC (Selective
Device Clear), GTL (Go To Local),
and SPE (Serial Poll Enable).
(Selective Device Clear) - The
command performs essentially
the same function as the DCL command
except that only the addressed
deviceresponds. Generally, instruments
return to their power-up default
conditions when responding to the
SDC command.
SDC
SDC
GTL (Go To Local) - The GTL command
is used to remove instruments from
the remote mode. With some instruments, GTL also unlocks front panel
controls if they were previously
locked out with the LLO command.
SPE (SerialPoll Enable), SPD (Serial
Poll Disable) -Serialpollingisused
to obtain the SRQ Status Register.
The StatusRegister contains important
operational information from the
unit requesting service. The SPD
command ends the polling sequence.
4-5
Message
Mnemonic
U n i l i n e Commands
Remote/REN
Interface Clear/IFC
universal Commands
Local Lock Out/LLO
Device Clear/DCL
Addressed command
Selected Device Clear/SDC
Go to Local/GTL
Serial Poll Enable/SPE
Unaddress Commands
Unlisten/UNL
Untalk/UNT
HP9825A
Command
Command
rem712
REMOTE712
11o7
clr7
c1r712
1c1712
rds(712)
HP86
IEEE-488
Bus Format
?U;
(IFC)
LOCAL LOCKOUT 7
CLEAR7
?U(LLO)
?U (DCL)
CLEAR712
LOCAL712
S=SPOLL712)
?U,(SDC)
?U,(GTL)
?U,(SPE)
?
Section IV
Model DRC-93C
4.6 PROGRAMMING INSTRUCTIONS
The Output Statement Requests are
sent by the BUS CONTROLLER to the
DRC-93C to tell the 93C what data
to output when data output is
requested.
These requests are
listed in Table 4-5 and the data
formats are described in detail in
the following tables as well as the
adjoining text associated with
those tables.
The following discussion references
The
the DRC-93C at address 12.
allowable address codes are given
in Table 4-2. Therefore, its Talk
ASCII Code is "L" and its LISTENER
ASCII Code is “,” (comma).
The
controller referred to in the
following discussion is the BUS
CONTROLLER and is normally a digital
computer. It should not be confused
with the temperature controller on 4.7 INSTRUMENT SETUP COMMANDS AND
the bus (DRC-93C). Set the IEEE REQUESTS
Address of the DRC-93C to 12 by
making Switches 5 and 6 CLOSED (1), 4.7.1 EOI Status - The ZN1 Command
4, 7 and 8 (OPEN) (0) and make sure
Switch 1 is OPEN (0) to select When EO1 (end or identify) is
(CR)(LF) as the terminating charac- enabled (”ZO";Table 4-6), the EO1
ters.
Note that this should be line is set active concurrent with
done prior to turning on the instru- the last byte of a transfer. Use
ment since the DRC-93C updates the of EO1 identifies the last byte
IEEE address on power-up only.
allowing for variable length data
Confirm that the address selected transmissions. EO1 can be disabled
is correct by holding in the REMOTE
("Z1";Table 4-6).
button for longer than one second
and observe the IEEE address on the 4.7.2 Interface M o d e - The MN1
front panel display as follows:
Command
LSCI
93c
Add12
4.6.1
Commands and Requests
The device-dependent commands to
program the DRC-93C are given in
Table 4-4. The 93C must be addressed
as a "LISTENER" to receive any
instruction or string of instructions from the Command list.
The DRC-93C input data format does
not require a set number or set
sequence of Commands to implement
proper instrument set-up. These
Commands are processed only after
the terminators [TERMl][TERM2] are
sent across the bus. The listing
and explanation of the 93C commands
are summarized in Table 4-4. There
are commands for Interface Setup,
Instrument Setup, Control Setup,
Scanner Setup, Status Register and
restoring Executable Programs.
COPYRIGHT 3/88 LSCI
4.7.2.1 Local - This message ["MO";
Table 4-61 clears the remote operation of the DRC-93C and enables
front panel operation.
Pressing
the front panel LOCAL button also
sets the instrument to local,
provided the button has not been
disabled by the Local Lockout
Message (see Section 4.7.2.3)
.
See Section 4.5.6 for a discussion
of the DRC-93C under local operation
while acting as a TALKER.
4.7.2.2 Remote - The DRC-93C is in
the local front panel mode when
first turned on. A remote message
["Ml"; see Table 4-61 allows the
93C to be controlled over the IEEE488 interface.
In Remote, the
front panel controls are disabled
(except the LOCAL button) and are
then controllable over the IEEE
Bus. The instrument's initial set
up is determined by the front panel
settings at the time when the
4-7
Section IV
Model DRC-93C
instrument is placed into Remote.
The DRC-93C may also be placed into
remote by pressing the REMOTE
Table 4-4.
button on the front panel or addressed to talk by the BUS CONTROLLER.
DRC-93C Command Summary of Instrument Setup
Summary of Input Command Formats.
Table
4-6
Interface Setup Commands
Selects EO1 status
Selects Remote Interface Mode
Changes terminating Characters
“Clear” Command
ZN1
MN1
TN1
C
Table
4-7
Table
4-9
4-10
Table
4-11
Instrument Setup Commands
FoCI
Select
F1C1
Select
F2CC1N1
Select
Select
F2SC1N1
F3CN1
Select
Select
F3SN1
F4CON, F4COFF Select
F4SON, F4SOFF Select
F5ON, FSOFF
Select
and F5CLR
Assign
NC1N1N2N3
S ,etc
PNlN2,etc.
INlN2,etc.
DN1N2,etc.
RN1
HN1N2
YAN1N2N3
or YBON2N3
Table
4-14
4-8
Curve Number for Input Channel selected
Set Point Input
Proportional (GAIN)
Integral (RESET)
Derivative (RATE)
Heater Range
Manual Heater %
Scanner Setup and Selection Commands
Set the Scanner channel dwell time
Enable the (S)CAN function.
Disable, or (H)old, the SCAN.
YH
Table
Control Units
Sample Units
Control (Setpoint) Sensor
Sample Sensor
the Control (Setpoint) Resolution
the Sample Resolution
the control Sensor Deviation ON or OFF
the Sample Deviation ON or OFF
the MATH Function ON, OFF or CLeaRed
Control Setup Commands
YS
4-13
Choices of the commands are:
Status Register Mask Command
QC1C2
Set the Status Register mask
Restoring Executable Programs Command
EN1N2C1-C60
Transmit (Restore) Program Step # N1N2 data
COPYRIGHT 3/88 LSCI
M o d e l DRc-93C
Local Lockout
4.7.2.3
- This message
[”m2”; Table 4-61 disables the DRC-
93C’s Local Front Panel controls,
including the LOCAL button.
The
message is in effect until the
message is cleared over the Bus or
power is cycled.
Many IBM PC IEEE-488 cards automatically place addressed instruments
into Local Lockout. To be able to
place the DRC-93C into Remote
without Local Lockout the user may
need to reconfigure his IEEE-488
card.
4.7.3
Terminating
characters
The TN1 Command
-
Terminating characters [”TO”, “T1”,
“T2” and “T3”; Table 4-63 are used
to indicate the end of a record.
Record terminators are used when
Table 4-5.
Table
Request
Section IV
the unit has completed its message
transfer.
Switch 1 of the IEEE
address defines the terminator
status.
If switch 1 is OPEN (0)
the terminator status is defined as
“TO” [ (CR)(LF)3 and terminator
status can not be changed over the
interface. When switch 1 is CLOSED
(1) the terminator status is defined
as “T1” [ (LF)) (CR)3 and the status
can be changed using the “TO”,
“T1”, “T2” or “T3” commands.
4.7.4
Clear
The (C)lear Message [see Table 4-41
sets the DRC-93C to the turn-on
state. This action is similiar to
turning the instrument OFF and then
turning it back ON, except that it
occurs in milliseconds, rather than
seconds and the DRC-93C does not go
through the power-up display sequence
.
DRC-93C Summary of Output Requests
output
Interface Status
Input and Option Card Data
4-6
w2
4-7
WD
4-9
WP
Set Point Data
4-10
w3
Control Data (Gain, Reset, etc.)
4-11
WY
Scan Data
4-13
WQ
Service Request Data
ws
wc
wo
Sample Sensor Data
Control Sensor Data
Sample & Control Sensors, Setpoint Data
MAX, MIN and MAXDEV Data
4-14
4-15
WI
WEN1N2
WM
COPYRIGHT 3/88 LSCI
Sample, Control,A and B Input Information
Program Step # N1N2 Data
4-9
Section IV
Model DRC-93C
T a b l e 4-6.
Command
ZN1a
DRc-93C Interface Setup Commands and Request Status
Functional Description
Selects IEEE EOI status. Forms of the command are ZO and Z1.
When N1is:
EOI Status is:
EOI line is set/accepted on last
character input or output.
EOI line is not set on last character
output or acknowledged on input.
0
1
MN1
Selects Remote Interface mode.
are MO, M1 and M2.
When N1is:
Mode is:
Local
Remote
Remote with Local Lockout
0
1
2
TN1
Changes terminating characters (when IEEE Address Switch #1
is CLOSED [1]). Forms of the command are TO, T1, T2 and T3.
When N1is:
Terminators are: b
(CR)(ENDC LF) [also with Switch OPEN]
(LF)(END CR) [default, unless changed]
(END LF)
(END DABd)
0
1
2
3
C
Forms of the comand
.
“Clear” command, returns unit to power up state (Restart)
Request
w2
Functional Description
Interface Status
-
ZN1,MN2,TN3
8 Characters plus up to 2 Terminators where:
ZN1
MN2
WI
TN3
is EOI status
is Mode status
is Terminator status
Input and Option Card Datae
A-C1C2C3C4C5C6C7,B-C8C9C10CllC12C13C14,
1-c15c16c17c18 , 2-c19c20c21c22 ,
3-c23c24c25c26
40 Characters plus up to 2 Terminators where:
a)
b)
c)
e)
4-10
c1-c7
c8-c14
c15-C18
c19-c2 2
C2 3-c2 6
is the A Input Card.
is the B Input Card.
is the Option 1 Present.
is the Option 2 Present.
is the Option 3 Present.
Ni corresponds to a numeric value (0 - 9)
The AND symbol
is used to indicate messages sent concurrently.
END = EOI;
d) DAB = last data byte
Ci corresponds to an alphanumeric (0 - F)
COPYRIGHT 3/88 LSCI
Model DRC-93C
4.7.5
The "W2" Data S t r i n g
For the case of W2, the data string
would have the following format:
ZO,M2,Tl[TEXMl][TERM2]
where the ZO, M2 and T1 are defined
in Table 4-6.
4.7-6 The “WI” D a t a S t r i n g
This Data String gives the input
cards present (9210, 9220, 9215,
9317C or 9318C) in Input A and B,
and if the analog option, interface
option or scanner is present. A
typical data string would be:
A-9220-P2,B-9318C ,1-8225,2-8223,
3-8229
which indicates 9220 cardconfigured
as a 100 ohm platinum input for
Input A; a germanium/carbon glass
input for Input B; a linear analog
option in Option Slot 1; a Rs-232C
option in Option Slot 2 and a
Scanner Card option in option Slot
3.
4.8 SELECTION OF QUANTITIES FOR TEE
CONTROL AND SAMPLE DISPLAYSUNITS, SENSORS, RESOLUTIONS AND
DEVIATION (TABLE 4-7)
4.8.1Units for Control Display and
Setpoint
The FOC1 Command
-
The FOC1 command set the temperature
or sensor units for the control
display and for the setpoint.
Sensor units (volts, ohms or nanofarads) are selected automatically
by the input card type. Consequently, the command for selecting
sensor units for control is FOS.
Temperature units are selected with
the same command with K, C, or F
substituted for S .
Note that only one choice of sensor
units (volts, ohms, or nanofarads)
is available which is dependent on
the input card type selected.
COPYRIGHT 3/88 LSCI
Section IV
4.8.2
Units for Sample DisplayThe F1C1 Cammand
The sample units may be set independently by the command F1C1. The
commands for selecting sensor units
are FlK, FlC, F1F and F1S.
4.8.3
Control Sensor
The F2CC1N1 Command
Selection-
The sensor to be selected for the
control display can be changed by
the F2CC1N1 command. The quantity
C1N1 is A0, Al, A2, A3, A4, or BO.
Examples: F2CA0, F2CB0, F2CA4.
4.8.4 Sample Sensor Selection
The F2SC1N1 Command
-
The sensor to be selected for the
sample display can be changed by
the F2SClN1 command. The quantity
C1N1 is A0, Al, A2, A3, A4, or BO.
Examples: F2SA0, F2SB0, F2SA4.
Caution is advised when using this
command i f the control sensor is
not on Channel B since this command
may then be switching the control
sensor.
4.8.5
Resolution for the Control
- The F3CN1 and F3SN1
and Sample
Commands
The resolution for the control and
sample displays can be set independently with the F3CN1 and F3SN1
commands, respectively. Thequantity
N1 is a number 0 thru 4 where
0
for a resolution of
1 for a resolution of
2 for a resolution of
3 for a resolution of
4 for a resolution of
xxx.
xxx.x
xxx.xx
xx.xxx
X.XXXX
Examples:
F3C1 for a resolution of xxx.x
on the Control Sensor Display
F3S3 for a resolution of xx.xxx
on the Sample Sensor Display
4-11
Section IV
Model DRc-93C
4.8.6 Selection of Deviation for
Control and Sample - The F4CON,
F4COFF, F4SON and F4SOFF Commands
Deviationoutputinsteadofmagnitude
and sign output can be selected for
the sample and control displays
independently using the F4CON,
F4COFF, F4SON and F4SOFF commands.
4.8.7 Selection of MATE Functions
-
ON, OFF and CLEAR
The F5ON, F5OFF
and F5CLR Commands
The MATH function can be turned on,
off or cleared using the F5ON,
F5OFF and F5CLR commands.
4.8.8 Sensor Curve # Selection The NC1N1N2N3 Command
The Curve Number to be selected for
the inputs can be changed by the
NC1N1N2N3 command.
The quantity
C1N1 is the input A0, Al, A2, A3,
A4, or BO. The quantity N2N3 is
the curve number from 00 thru 30.
Examples:
NA000, NA006, NA405,
NB002, etc.
4.8.9 The A and B Sensor I D Informa- The AC1C2 and Bc1C2 commands
tion
The purpose of this command is to
select Filtering of the A or B
input, whether the Remote Position
Data is used to establish the curve
numbers, the Temperature Coefficient
sign for the 9215 card, and whether
or not thermal correction is desired
on the 9317C/9318C cards.
Table 4-8 defines C1 and C2 in the
AC1C2 and BC1C2 Commands.
C1
defines whether the Remote Position
Data should be used to select the
Curve Number. C2 defines whether
the thermal correction is on or off
on the 9317C/9318C cards, filtering
on or off, and the sign of the
temperature coefficient with a 9215
Capacitance Card.
- Enable digital filtering to
be used to determine display value.
A02
4-12
A10 - Enables the REMOTE SENSOR
ID. If the remote position data is
0, then the sensor curve reverts to
the curve in A00 (or BOO) rather
than being selected from the REMOTE
SENSOR ID Table.
A12 - Enable digital filtering in
addition to the A10 description.
4.8.10 The “WD" D a t a S t r i n g
An example of the data received
when requesting Sample, Control, A
and B information using the WD
command is as follows
A0,K,3,N,B0,K,2,N,00,A00,02,00,00,
00,00,B02,04
The above string indicates that the
Sample Sensor is A0, sample units are
kelvin, sample resolution is 3
(xx.xxx) and the sample form isnormal;
the Control Sensor is BO, control
units are in kelvin, control resolution
is 2 (xxx.x) and control form is
normal; the remote position is off;
the SENSOR A ID indicating that the
Digital Filtering is Off and theREMOTE
SENSOR ID is off; the curve being
used for INPUT A0 is 2 and Al, A2,
and A3 are using curve 0; the
SENSOR B ID indicates that Digital
Filtering for this channel is On
and the curve assigned is 4.
Both channels are using the DT-470
“Curve 10”, the difference is that
INPUT A is set for an upper limit
of 325K and INPUT B is set with an
upper limit of 475K.
4 . 9 THE CONTROL COMMANDS
4 . 9 . 1 The Set Point Value
The S Command
-
The set point is sent from the
controller to the DRC-93C in a free
field format of which examples are
given in Table 4-9. Note that the
sign only has to be present if
negative Celsius or fahrenheit
settings are desired. Although
COPYRIGHT 3/88 LSCI
Section IV
M o d e l DRC-93C
Table 4-7.
DRC-93C Command Summary for Instrument Setup
Command
Functional Description
Selection of Units, Sensors, Resolution, and Deviation
F0C1
F1C1
Function 0 - Select Control (Setpoint) Units.
Forms of the command are F0K (kelvin), F0C (Celsius),
F0F (fahrenheit), and FOS for Sensor Units in volts,
ohms or nanofarads.
Function 1 - Select Sample Units.
Forms of the command are F1K (kelvin), F1C (Celsius),
F1F (fahrenheit), and F1S for Sensor Units in volts,
ohms or nanofarads.
F2CC1N1
Function 2C - Select Control (SetPoint)Sensor.
Formsof the command are F2CA0, F2CA1 , F2CA2 , F2CA3*,
F2CA4 and F2CB (or F2CB0).
With 8229 Scanner Card Only.
F2SC1N1
Function 2s
Select sample Sensor.
Formsof the command are F2SA0, F2SA1*, F2SA2*, F2SA3*,
F2SA4 and F2SB (or F2SB0).
With 8229 Scanner Card Only.
F3CN1
-
Function 3C
-
Select the Control (Setpoint) Resolution. N1 is
(xxx.xx), 3 (xx.xxx) or 4 (x.xxxx).
Forms of the command are F3C0, F3C1, F3C2, F3C3 and F3C4.
0 (xxx.), 1 (xxx.x),2
F3SN1
Function 3s - Select the Sample Resolution. N1 is
0 (xxx.), 1 (xxx.x),2 (xxx.xx), 3 (xx.xxx) or 4 (x.xxxx).
Forms of the command are F3S0, F3S1, F3S2, F3S3 and F3S4.
F4CON
F4COFF
Function 4C
- Select the Control Sensor Deviation ON
Function 4s
-
F5ON
F5OFF
F5CLR
Function F5
- Select the MATH
AC1C2
or
BC1C2
Input A ID and B ID. C1C2 are 00 thru 1F. Forms of
the command are A00 thru AFF. C1 ranges between 0 and F.
If C2 is between 0 and 7, then C1 selects the Sensor Curve
number 00 (0) thru 15 (F) If C2 is between 8 and F, then
C1 corresponds to a Remote Position between 0 and F.
F4SON
F4SOFF
or OFF.
Select the Sample Sensor Deviation ON or OFF.
Function on, off or cleared.
NC1N1N2N3 Function N assigns Curve Number to Input Channel. Forms of
the command are NA000 thru NA031 (NA431 with Scanner Card)
and NB000 t h r u NB031.
COPYRIGHT 3/88 LSCI
.
4-13
Section IV
Model DRC-93C
DRC-93C Request Summary for Instrument Setup
T a b l e 4-7 Cont'd.
Request
WD
Output of Instrument Variables
Sample, Control, A and B Input Information
C2C3,C3,N1,C4,C5C6,C7,N2,C8,C9C10,AC11C12,
N3N4 ,N5N6, N7N8 , N9N10 ,N11,N12, Bc13c14 , N13N14
46 characters plus up to 2 terminators where:
is
is
is
is
C1C2
c3
N1
c4
is
c5c6
c7
N2
c8
C9C10
C11C12
N3N4
N5N6
N7N8
N9N10
N11N12
is
is
is
is
is
is
is
is
is
is
the
the
the
the
the
the
the
the
the
the
the
the
the
the
the
Sample Sensor A0, Al, A2, A3, A4 or BO.
Sample Units K, C, F, V, N or R.
Sample Resolution 0 (xxx) through 4 (x.xxxx)
Sample Form
N for norma1,D for Deviation
Control Sensor A0, Al, A2, A3, A4 or BO.
Control Units (K, C, F, V, N or R)
Control Resolution 0 (xxx) through 4 (x.xxxx)
Control Form - N for normal, D for Deviation
Remote Position (00 through 1F).
-
.
A ID (00 through 1F).
A0 curve number (00 through
A1 curve number (00 through
A2 curve number (00 through
A3 curve number (00 through
A4 curve number (00 through
30).
30).
30)
30).
30).
.
C13C14 is the B ID (00 through 1F).
N13N14 is the B Curve Number (00 through 30).
T a b l e 4-8,
1
1
C1 and C2 in A ID and B ID, the SENSOR ID’S
2
2
c2
3
4
4
8
4
C1.
2
4 i s MSB, 1is LSB
Binary Weighting
Remote Position (On), Curve # (Off) Bit
Thermal Correction
Digital Filtering
Thermal Correction or Ice-Point Compensation
8
3
4
C1
2
Curve # Select Curve #
or Remote (0) or Remote
Position Position (8)
0 to F
“
“
“
II
“
“
“
4-14
or 8
1 or 9
2 or A
3 or B
4 or C
]
or D
6 or E
7 or F
0
1
1
c2
9317C/9218C
Card Thermal
Correction
OFF
OFF
OFF
OFF
ON
ON
ON
ON
(0)
(0)
(0)
(0)
(4)
(4)
(4)
(4)
9215 Card
Digital
Filtering Temperature
Coefficient
OFF
OFF
ON
ON
OFF
OFF
ON
(0)
(0)
+ (0)
(0)
(0)
+ (0)
-
(1)
(2)
(2)
+ (0)
(2)
ON (2)
+ (0)
-
-
-
(1)
(1)
(1)
COPYRIGHT 3/88 LSCI
Model DRC-93C
input range may be above the values
possible for the various sensors,
the set point is limited by the
input card present as shown in the
table.
Note that the temperature
limit can be different for the DT470 depending on whether curve 02
(324.9K) or curve number 04 (474.9K)
has been selected. If a number
Command
or
or
or
or
above the limitation for the card
is entered, the set point is set to
the upper temperature limit. Also
note that an S sent by itself to
the 93C sets the set point to 0
kelvin (or its equivalent in the
units chosen) which will result in
shutting down the heater output
stage of the temperature controller.
DRC-93C Command/Request Summary for Setpoint Setup
Table 4-9.
or
or
or
or
or
or
Section IV
Functional Description
S
SN1
SN1.N2
SN1N2
SN1N2.N3
SN1N2N3 .N4
SN1.N2N3
etc.
( )SN1
( )SN1.N2
( )SN1N2
( )SN1N2.N3
etc
.
Input Card
9210/20-3
9210/20-6
Set Point Input. The decimal point is “FREE FIELD"
and its allowable position depends on the control
units. Limits are
Units
Range
K
c,F
V
R
N
through
999.9
through
999.9
through
9.9999
through 99999
through
99.999
or 999.99
The Set Point is limited based on input card and
Sensor. Lower limit is 0 K (-273.1 "C or -459.6 °F).
Sensor Type
0
-999.9
0.0000
0
0
K
Upper Set Point Limit
"C
°F
Sensor Units
“
51.7
“
125.1
“
“
“
“
“
“
9317C
9318C
9215-15
9215-150
DT-470, DT-500
TG-100,TG-120
Germanium/Carbon Glass
Germanium/Carbon Glass
CS-400,CS-501
CS-401,CS-501
9210/20-3
DT-470
474.9
201.7
9220-P2
9220-P3
9220-R1
PT-100 Series
PT-1000 Series
Rhodium-iron
999.9
“
526.7
“
“
N/A
N/A
N/A
N/A
“
“
N/A
N/A
395.1
980.1
“
“
2.9999
6.5535
9999.9
99999
29.999
149.99
volt
volt
ohms
ohms
nF
nF
2.9999 volt
299.99 ohms
2999.9 ohms
99.999 ohms
Output of Instrument Data
Request
WP
324.9
Set Point Data
-
( )N11N12N13(. )N14N15( )
8 Characters plus up to 2 terminators where the N11-N15
variations are the same as for WO (see Table 4-15).
COPYRIGHT 3/88 LSCI
4-15
Section IV
M o d e l DRC-93C
Note: Although limitations on the
range of the set point are set
within the software when in temperature units; these limits are not
possible for sensor units due to
the different characteristics for
each sensor.
Since the set point is soft, the
transition from REMOTE to LOCAL
does not result in a change in the
set point.
4.9.2 The “WP" R e q u e s t D a t a S t r i n g
This request is a subset of the
“WO” command; the “WP” command
giving the set point value by itself.
4.9.3 SettingtheGAIN(proportional)
-The P Comnand
The gain is a multiplier between
0.1 and 99., a range of 990, i.e
99./0.1 = 990. A gain of 0.0 is
not allowed. The format is free
field with examples of the command
being P.1, P0.1, P9, P9., P9.0,
P99, P99., etc.
The string P987.12 will be interpreted as P87, i.e., the first
valid combination will be retained.
A P transmitted by itself is equivalent to PO or P0.0 and sets the
gain to 0.1.
.
4 9.4 Setting the RESET
-The ICommand
(Integral)
The reset is set from 0.1 through
99 (1to 990) seconds. Like the gain
command, it is free field with the
same characteristics and format. A
setting of 0.0 turns the reset off.
4.9.5 Setting the RATE ( D e r i v a t i v e )
-TheDCammand
The rate is also set in seconds/10
(from 0.1 to 99). It handles its
input format exactly the same as
both gain and reset commands. A
setting of 0.0 turns the rate off.
4-16
4.9.6
Heater Range
- The R
command
The heater range can be changed
over the bus with the RN1 command.
R6 and up are equivalent to the R0
command (see Table 4-10).
4.9.7 % Manual H e a t e r Power
The H Command
-
The Per Cent Manual Heater Power
can be set between 00 and 99 with
this command. Total power can be
greater or less than this setting,
dependent on control settings and
actual control sensor temperature.
4.9.8 The “W3” D a t a S t r i n g
The settings for the gain, rate,
reset, manual heater power, heater
range as well as the instantaneous
% of Heater Power can be transmitted
from the DRC-93Cwith the “W3”command.
The command “SPIDR” or any combination without a value following the
letter sets the chosen parameters
to 0, e.g., “SP” sets the set point
and gain to 0.
4.10
THE
SCANNER
INPUT CARD
.
4 . 1 0 . 1 SCAN Programming Instructions
NOTE: The YA, YB (Table 4-11) and
Y2S (Table 4-7) commands should be
issued when the SCAN mode is Holding.
changing a SCAN time or Scannerchannel
while the unit is actively scanning
may cause unpredictable results.
4.10.2 Setting the D w e l l Time The YAN1N2N3 and YBON2N3 Commands
The time spent on a given scanner
channel can be varied between 0 and
99 seconds by setting the dwell
time for that channel. This can be
done over the IEEE-488 Bus with
these commands or from the front
panel. Setting the dwell time to 0
skips that channel.
COPYRIGHT 3/88 LSCI
Section IV
M o d e l , DRc-93C
Table 4-10. DRC-93C Command/Request Summary for the Control Parameters
Comand
Functional Description
S e t t i n g of a l l other Control Parameters
pN1
N2
o r pN1N2
Proportional (GAIN).
N1N2 is 0.1 through 99. Examples
the command are P, PO, P0.0 and P99.
IN1.N2
Integral (RESET). N1N2 is 0.0 (OFF) through 99.
(three c h a r a c t e r s including the decimal p o i n t ) .
Forms of the comand are I O (10.0) through I99.
DN1. N2
Derivative (RATE). N1N2 is 0.0 (OFF) through 99.
(three c h a r a c t e r s including t h e decimal p o i n t ) .
Forms of t h e command are DO (D0.0) through D99.
or IN1N2
o r DN1N2
N1
0
1
2
3
4
5
Range
-4
-3
-2
-1
MAX
Current
mA
mA
mA
mA
A
00 t o 99 % of H e a t e r Range
Functional Description
Request
Control Parameters
20 c h a r a c t e r s p l u s
N1N2N3
is the
N4N5N6
is t h e
N7N8N9
is t h e
N10
is the
N11N12N13 is the
is the
N14N15
4.10.3
Heater
0
10
33
100
330
1
OFF
% Manual H e a t e r Power.
HN1N2
w3
Forms of t h e
N 1 is 0 through 5.
command are R0 through R5.
Heater Range.
RN1
N1N2N3,N4N5N6,N7N8N9,N10,N11N12N13,N114N15
up t o 2 terminators where:
G a i n Value
Rate Value
R e s e t Value
H e a t e r Range
% of H e a t e r Power or Current out.
% of Manual Heater Power o r Current O u t
Enabling the Scan Function
- The YS Command
Upon sending the Y S command from
the BUS CONTROLLER, the DRC-93C
s t a r t s its scan of the i n p u t s f r o m
t h e channel input which it is
currently on. The scan sequence is
A,
1(Al), 2 ( A 2 ) , 3(A3),4(A4), A,
etc. with any channel whose dwell
COPYRIGHT 3/88 L S C I
t i m e is set t o zero being skipped.
It is strongly recommended t h a t t h e
control channel be t h e B channel
when t h e scanner is used. I f it is
not, it w i l l be changed i f a scanner
card is present, since one current
source is a s s o c i a t e d w i t h t h e A0-A4
inputs.
4-17
Section IV
Model DRC-93C
Table 4-11. DRC-93C Command/Request Summary for Scanner
Command
Functional Description
Set the AN1 (A0 - A4) or BO Scanner channel dwell time
YAN1N2N3
or YBON2N3
time to N2N3 seconds. N2N3 is 00 to 99 seconds. Forms
(After YH cmmd) are YA000 thru YA099, YA100 thru YA199, etc.
YS
Enable the (S)CAN function.
YH
Disable, or (H)old, the
Request
WY
SCAN.
Functional Description
scan Information ClrC2C3,C4C5,C6C7,C8c9,c10c11,C12C13,C14C15
22 characters plus up to 2 terminators where:
C1
is the SCAN status, (H)olding or (S)canning.
C2C3-C12C13 is the A0 - A4 and BO dwell times in seconds.
is the SCAN position A0, Al, A2, A3 or A4.
c14c15
a) Ci corresponds to an alphanumeric
4.10.4 Holding the Scan Function
-TheYHcommand
The Scan can be stopped any time
over the IEEE-488 Bus by sending
out the YH command. The scanner
should be in hold when any of the
other scanner commands are sent to
the scanner.
4.10.5 The “WY" Data S t r i n g
This request includes whether the
instrument is scanning or holding,
thechannel dwell informationandthe
scan position.
THE SERVICE REQUEST, STATUS
REGISTER, STATUS REPORTS, AND THE
STATUS REGISTER MASK
4.11
As mentioned earlier, a Service
Request can be initiated by the
DRC-93C to indicate a function has
been performed, or a limit, overload
or error has been encountered. The
DRC-93C does this by pulling its
SRQ (Service Request) management
4-18
line low. The BUS CONTROLLER uses
the serial poll (SPOLL) to obtain
the contents of the register in the
DRC-93C called the Status Register.
The DRC-93C Status Register is a
single byte of data from the DRC-93C
containing
five bits called the
Status Reports. These StatusReports
indicate when certain processes are
complete, whether the channel was
changed, or a limit, overload or
error encountered. The S t a t u s Register
Mask is provided so that the Status
Request interrupt and undesired
Status Reports can be inhibited.
Reading the Status Register resets
the Status Register to all zeros so
that only new status reports will
be registered by the DRC-93C.
Thus, through the SRQ management
line and the Status Register, the
DRC-93C is able to signal Status
Reports on five conditions immediately to the BUS CONTROLLER.
It is possible to disable the DRC93C SRQ line thereby preventing the
COPYRIGHT 3/88 LSCI
Section IV
M o d e l DRC-93C
DRC-93C from interrupting the BUS
CONTROLLER.
However, the BUS CONTROLLER can still read the Status
R e g i s t e r t o determine appropriate
instrument conditions.
4.11.1
The Service Request
Service Request Message is
independent of a l l other IEEE-488
a c t i v i t y and is s e n t on a s i n g l e
l i n e called the SRQ l i n e . When the
Service Request is sent and more
than one instrument on t h e Bus has
the c a p a b i l i t y to send thismessage,
the BUS CONTROLLER must decide
which instrument is sending the
request. T h i s is done by conducting
a “Serial Poll” of the instruments
on t h e Bus. The instrument polled
responds by sending a Status Register. The Status R e g i s t e r indicates
whether the device has requested
service and i f so, f o r w h a t reason.
The
Once t h e reading on a given channel
becomes stable (or v a l i d ) , a service
request is issued by the DRC-93C
provided that B i t 6 i n the Status
Register Mask is set (See 4.11.2.5)
W i t h the SRQ b i t of the Status
Register m a s k disabled, no SRQ
i n t e r r u p t by t h e DRC-93C w i l l be
generated, however, the BUS CONTROLLER can still read t h e Status
Register t o determine appropriate
instrument conditions.
.
4.11.2
The Status
Status Reports
Register
and
Status Register is a
s i n g l e byte of data from the DRC-93C
containing
f i v e b i t s called the
Status Reportswhich give information
indicatingwhich process is complete,
whether the channel w a s changed, o r
a l i m i t , overloador errorencounterThe DRC-93C
ed
.
The Status Register can be read a t
any t i m e by means of a Serial P o l l
Enable command.
Reading the Status Register resets
the Status R e g i s t e r t o a l l zeros so
COPYRIGHT 3/88 LSCI
that only new s t a t u s reports w i l l
registered by the DRC-93C.
Executing the Q command (Section
4.11.3)
a l s o resets the Status
Register t o a l l zeros. Reading the
Status Register resets a l l of i t s
b i t s t o zero.
be
Status Reports 0 and 1 and Control Data Ready.
B i t 0 of the Status Register is set
when a v a l i d Display data reading
is available.
B i t 1 of the Status
Register is set when a v a l i d Control
data reading is available.
I f the
Service Request is enabled, either
one of these being set w i l l cause
the DRC-93C t o p u l l the SRQ management low t o signal t h e BUS CONTROLLER. These b i t ( s ) are reset t o
zero upon reading the Status Register
on response t o a serial p o l l o r i f
the reading is no longer valid.
4.11.2.1
Display
These functions can be inhibited by
turning their corresponding b i t s i n
the Status Register mask o f f .
4.11.2.2
Status Report 2 - The
Control Channel L i m i t .
When the
control sensor reading gets w i t h i n
the chosen l i m i t from t h e set point,
b i t 2 is set i n the Status Register.
I f the Service Request is enabled
this b i t being set w i l l cause the
DRC-93C t o p u l l the SRQ management
low t o signal the BUS CONTROLLER.
As w i t h a l l of the Status Reports,
this b i t is reset t o zero upon
reading t h e Status Register.
The
b i t w i l l not r e v e r t t o zero i f the
control sensor difference from the
set point l a t e r exceeds the l i m i t
selected.
The control channel l i m i t is entered
using the Q command.
(See Section
4.11.3.2).
This function can be inhibited by
turning off b i t 2 i n the Status
Register mask.
4.11.2.3
Status Report 3 - Display
Sensor Channel Change. B i t 3 of the
4-19
Section IV
Model DRC-93c
Status Register is set when a
channel change occurs for the
Display. If the Service Request is
enabled this bit being set will
cause the DRC-93C to pull the SRQ
management low to signal the BUS
CONTROLLER.
This Status Register
bit is reset to zero upon reading
the Status Register.
This function can be inhibited by
turning off the bit 3 in the Status
Register Mask.
-
Status Report 5
Overload
If the display
has an overload condition on any
selected channel or an error occurs,
then bit 5 of the Status Register
is set and a Service Request is
issued if enabled.
This Status
Register bit is reset to zero upon
reading the Status Register.
4.11.2.4
Error Indicator.
This function can be inhibited by
turning bit 5 off in the Status
Register Mask.
4.11.2.5
When operating without the
ServiceRequest it is still possible
for the BUS CONTROLLER to read the
Status Register.
The Service
Request is inhibited by turning off
the SRQ bit (bit 6 ) in the Status
Register Mask.
However, it must be understood that
certain bits in the Status Register
are continually changing.
The
Status Reports for the Overload/Error, Display Data Ready, and Control
Data Ready are continuously updated
to reflect current instrument
status.
The Channel Change and
Control Channel Limit once encountered are latched (set to 1) and
remain latched until the Status
Register is read.
4.11.3
The Status Register Mask
The Qc1c2 Command
-
The Status Reports listed above may
not be desired or perhaps only a few
are of interest. TheStatusRegister
4-20
Mask is provided to allow the user
to select whether he wants a given
Status Report or not. The various
bits of the Status Register Mask
enable the various Status Reports.
The bits in the Status Register
Mask have the same bit position as
the bits in the Status Register.
Only those bits which are allowed
by the Status Register Mask Command
are potentially changeable in the
Status Register.
Note that the
corresponding bit in the Status
Register Mask determines whether
its counterpart in the Status
Register can change.
The Status Register Mask is shown
in Figure 4-2. It consists of 8
bits, one bit (bit 6 ) which determines whether the DRC-93C is to
report via the SRQ line and five
bits to determine which Status
Reports to make. Bit 6 is the SRQ
(Service Request) bit and if set
allows the DRC-93C to send out a
Service Request on the SRQ IEEE-488
line. If the SRQ bit is not set
(off) then the DRC-93C is inhibited
from producing a Service Request.
The Status Register can still be
read by the BUS CONTROLLER to
examine the Status Reports, but the
BUS CONTROLLER will not be interrupted by the Service Request.
Five of the other seven bits select
which of the five Status Reports to
make. If one of these five bits is
set (on), the DRC-93C will update
the corresponding Status Report bit
in the Status Register. Then if
the SRQ bit (bit 6 ) of the Status
Register Mask is set, the DRC-93C
will send out a Service Request on
the SRQ IEEE-488 line. By means of
a serial poll enable (SPE), the BUS
CONTROLLER determines that the DRC93C has sent out a service request
and then reads the Status Register.
Reading the Status Register resets
the Status Register to all zeros.
Executing the Q command also resets
the Status Register to all zeros.
The Status Register Mask command is
COPYRIGHT 3/88 LSCI
Section Iv
Model DRC-93C
the ASCII letter Q followed by two
alphanumerics representing the most
significant four bits and the least
significant four bits, respectively.
Note that the controller can be
programmed for more than one set of
conditionssimultaneously. Toenable
the Service Request, Bit 6 must be
a 1.
Status Register Mask Bits
and 1
Sample and Control Data
Ready Enables. If either Bit 0 or
Bit 1 of the Status Register Mask
is set (1), then for that data, the
corresponding bit in the Status
Register is set when a valid data
reading is available.
4.11.3.1
0
-
4.11.3.2 Status Register Mask Bit 2The Control Channel Limit Enable.
If the control channel limit (Figure
4-2, Bit 2) is selected, the limit
must follow the Q comand and is in
a free field format. Examples are
XXX.X, .x, x.x, xx.x, x., xx., etc.
If Bit 2 of the Mask is set (1),
then when the control sensor reading
gets within the chosen limit from
the set point, the corresponding
bit is set in the Status Register.
4.11.3. 3 Status Register Mask Bit 3Sample Sensor Channel Change Enable
If the Sensor Channel Change (Bit
3) is selected, then bit 3 in the
Status Register is set when a
channel change occurs.
4.11.3.4
Status Register Mask Bit 5
- Overload/Error
Indicator Enable.
If the Overload/Error Indicator
Enable Bit (5) is set, then if the
display has an overload condition
on any channel or an error occurs,
the corresponding bit on the Status
Register is set and a Service
Request is issued if the SRQ bit of
the mask is a 1.
The user can
check which overload or error was
detected by sending the Output Data
Statement W0 (See Section 4.14.2
and Table 4-15).
For example, in Figure 4-2, Q21
COPYRIGHT 3/88 LSCI
will allow the setting of the
Overload/Error Indicator and Sample
Data Ready bits in the Status
Register, but will not send an
Service Request if either condition
is met.
Q61 however will allow
either of these bits to be set and
when either is set, an Service
Request will be issued by the DRC93C over the IEEE-488 Bus. This
Service Request will remain on the
Bus until either a Serial poll is
initiated or the cause of the
setting of the SRQ is eliminated.
The Status Register mask and control
channel limit is part of the powerup save settings like the set point
and units. It is updated on powerup to the last settings with internal
switch 2 set.
On power up the
Status Register mask is set to 00
and the control channel limit to
000.0 if switch 2 is off.
4.11.3.5
Examples for setting Mask
Example #1 - Q61 - Sample Data
Ready with the Service Request bit
(SRQ) on. - With the SRQ bit of the
Status Register mask enabled, the
DRC-93C SRQ interrupt will be
generated. The BUS CONTROLLER can
readthe Status Registerto determine
appropriate instrument conditions.
In this case bits 1 is continuously
updated to reflectcurrentinstrument
status of the Sample Data Ready. Q61
also results in a service request
if an \
is indicated.
Example #2 - Q2F000.1 - All Status
Reports with the SRQ bit off. With the SRQ bit of the Status
Register mask disabled, no SRQ
interrupt by the DRC-93C will be
generated, however, the BUS CONTROLLER can still read the Status
Register and this command will give
all five Status Reports.
Example #3 - Q06000.1 - Enable the
Control Data Ready and Control
Channel Limit with a band of 0.1
about the control point.
4-21
Section IV
Figure 4-2.
Model DRC-93C
DRC-93C Status Register Mask and Status Register Format
Table 4-12.
Note: On means 1.
4-22
Commands to F i x the Status Register Mask
Those entries left blank are OFF (0).
COPYRIGHT 3/88 LSCI
Section IV
Model DRC-93c
T a b l e 4-13.
DRC-93C Command/Request Summary for Status Register Mask
Command
QC1C2e
Functional Description
The Status Register mask is set using the Q command.
Forms of the command are Q0C2, Q2C2, Q4C2, Q6C2 and
QC12,
QC15, QC16,
When C1 is:
Status Register Mask is:
Service Request OFF;Error/Overload
Indicator Request OFF
Error/Overload Indicator Request ON
Service Request is ON;
0
2 or 6
4 or 6
When
c2 is:
Status Register Mask Status is:
Sample Data, Control Data and Limit OFF
Sample Data Service Request is ON
Control Data Service Request is ON
Control Channel Limit SRQ is ON
0
1, 3, 5 or 7
2, 3, 6 or 7
4, 5, 6 or 7
Request
WQ
Output of Instrument Setup
SRQ Mask Data
-
8 Characters plus up to 2 terminators where:
C1C2
is the SRQ Mask Byte
is the control channel limit band
4.11.3.6
Status Register Mask at
Power Up. The Status Register Mask
is saved at power-down, provided
switch 2 of the internal 8 switch
package is on.
4.11.4
The “WQ” Data String
This command gives the Status
Register Mask and control channel
limit information.
4.12 SAVINGANDRESTORINGEXECUTABLE
(INTERNAL) PROGRAMS
Requesting a Program Step
for Saving - The WEN1N2 Command
4.12.1
The WEN1N2 command requests the
Program Step #
from the 93C.
The data of the Program Step will
be in the next output transmitted
from the instrument.
The Data
COPYRIGHT 3/88 LSCI
consists of the the Program Step #
in ASCII followed by sixty characters. These characters are to be
stored by the user for later transmission back to the instrument by
the EN1N2 command described below.
Examples of this command and the
EN1N2 command are given in section
4.12.3.
4.12.2
Transmi
itting a Program Step
to the 93C - The EN1N2c1-C60 Command
The E command requests that Program
Step # N1N2 and its data (C1 thru
c60) be sent to the 93C. The form
is EN1N2C1,-C60. The data must have
been previously received from t h e
instrument using the WEN1N2 command
and stored for transmission back to
the instrument using this command.
Examples of the E command in conjunction with the WEN1N2 command
are given below.
4-23
Section IV
T a b l e 4-14.
Model DRC-93C
DRC-93C Command/Request Summary for Program Step
Command
Functional Description
Request
Functional Description
4.12.3 Examples of Saving and R e s t o r i n g Executable (Internal) Program Steps
4.12.3.1 Program to Request and Store Program Step # 1 t h r u 10 using the HP86B
The following program for the HP86B requests and get Program Steps #01 thru
#10 and stores the data in a file called “PROGRAM” on afloppy with volume
label “93C”. To initialize an unused floppy in slot 0 for this purpose the
command INITIALIZE “93C”, “D700” can be executed.
10 REM “STORE”
20 REM PROGRAM TO READ AND STORE AN INTERNAL PROGRAM
30 REM SET IEEE ADDRESS TO 12
40 ADDRESS SWITCH 1 OPEN (0) TO GET (CR)(LF)
50 DIM A$[62],Nl$[1],N2[1]
60 REM CREATE "PROGRAM1.93C" ,99,32
! ONLY USE FIRST TIME TO CREATE FILE
70 ASSIGN# 1 TO "PROGRAM1.93C"
! OPEN THE FILE
! FOR PROGRAM STEPS #01 THRU #10
80 FOR I=1 TO 10
90 IF I<10 THEN GOTO 140
100 I$=VAL$(I)
110 Nl$=I$[1,1]
120 N2$=1$[2,2]
130 GOTO 160
140 Nl$="0"
150 N2$=VAL$ (1)
160 OUTPUT 712;”WE”;N1$;N2$ ! SEND THE WE COMMAND REQUESTING PROGRAM STEP I
170 ENTER 712; A$
! GET PROGRAM STEP I
180 DISP A$
! DISPLAY ON THE SCREEN
190 PRINT# 1; A$
! SAVE PROGRAM STEP I IN THE FILE
200 NEXT I
210 ASSIGN# 1 TO *
! CLOSE THE FILE
220 END
4-24
COPYRIGHT 3/88 LSCI
Section IV
Model DRC-93C
4.12.3.2
Program to Restore Program Step # 1 thru 10 using the HP86B
*The following program for the HP86B restores Program Steps #01 thru #10
from a file called “PROGRAM1” previously stored a floppy with the volume
label "93C".
10 REM "RESTORE"
20 REM PROGRAM TO RESTORE THE INTERNAL PROGRAM AND PRINT ON THE SCREEN
30 DIM A$[62],Nl$[1],N2$[1]
40 REM "PROGRAM1.93C" WAS CREATED AND
50 ASSIGN# 1 TO "PROGRAM1.93C"
!
60 FOR I=1 TO 10
!
70 READ# 1 ; A$
!
80 OUTPUT 712 ;”E”;
; A$
!
90 DISP A$
!
100 WAIT 200
!
110 NEXT I
120 ASSIGN# 1 TO *
!
130 END
4.12.3.3
WRITTEN BY PROGRAM STORE
OPEN THE FILE
PROGRAM STEP #01 TO #10
GET PROGRAM STEP I FROM THE FILE
SEND PROGRAM STEP I
DISPLAY THE PROGRAM STEP ON THE SCREEN
WAIT 200 MILLISECONDS
CLOSE THE FILE
National Instruments GWBASIC and BASICA IBM Example of WEN1N2 Request
This program will store Programs Step # 1 t h r u 10 in File "PROGRAM1” on Disk
A: using GWBASIC or BASICA and the National Instruments GPIP-PC2 IEEE-488
Card for the IBM PC and compatibles.
10 CLEAR
,60969 ' BASIC DECLARATIONS
20 IBINITl = 60969 ‘ This number is different for each computer
30 IBINIT2 = IBINITl + 3
40 BLOAD “bib.m",IBINITl
50 CALL IBINITI(IBFIND,IBTRG,IBCLR,IBPCT,IBSIC,IBLOC,IBPPC,IBBNA,IBONL,
IBSRC,IBSRE,IBSRV,IPPAD,IBSAD,IBIST,IBDMA,IBEOS,IBTMO,IBEOT,IBRDF,IBWRTF)
60 CALLIBINT2(IBGTS,IBCAC,IBWAIT,IBPOKE,IBWRT,IBWRTA,IBCMD,IBCMDA,IBRD,IBRDA,
IBSTOP,IBRPP,IBRSP,IBDIAG,IBXTRC,IBRDI,IBWRTI,IBRDIA,IBWRTIA,IBSTA%,IBERR% ,IBCNT%)
'93C is IEEE address label set up when running IBCONE
70 TEMP$="93C”
80 CALL IBFIND(TEMP$,TEMP%)
'Required command to address 93C
90 OPEN “A:PROGRAM1” FOR OUTPUT AS #1
'Open file to store data
100 FOR I=1 TO 10
'Program Steps #01 TO #10
110 IF I<10 THEN GOTO 150
120 Nl$=MID$(STR$(I) ,2,1)
140 GOTO 160
150 N1$="0"
160 N2$=RIGHT$(STR$(I),1)
'Assemble command
170 B$=”WE”+Nl$+N2$
'Add CR and LF to command
180 B$=B$+CHR$ (13)+CHR$ (10)
'Send request to 93C
190 CALL IBWRT(TEMP%,B$)
'Get
data from 93C
200 CALL IBRD(TEMP%,A$)
'Display
received
information on screen
210 PRINT A$
220 PRINT# 1;A$
'Save in file “A:PROGRAM1”
230 NEXT I
240 CLOSE 1
250 END
COPYRIGHT 3/88 LSCI
4-25
Section IV
4.12.3.4
Model DRC-93C
National Instruments GWBASIC and BASICA IBM Example of E Command
This program will restore Programs Step # 1 thru 10 previously stored in file
“PROGRAM1” on Disk A: using GWBASIC or BASICA and the National InstrumentsGPIPPC2 IEEE-488 Card for the IBM PC and compatibles.
CLEAR
,60969
'BASIC DECLARATIONS
'This number is different for each computer
IBINITl = 60969
IBINIT2 = IBINITl + 3
BLOAD “bib.m”,
IBINITl
CALL IBINIT1(IBFIND,IBTRG,IBCLR,IBPCT,IBSIC,IBLOC,IBPPC,IBBNA,IBONL,
IBRSC,IBSRE,IBRSV,IPPAD,IBSAD,IBIST,IBDMA,IBEOS,IBTMO,IBEOT,IBRDF,IBWRTF)
60 CALL IBINT2(IBGTS,IBCAC,IBWAIT,IBPOKE,IBWRT,IBWRTA,IBCMD,IBCMDA,
IBRD,IBRDA,IBSTOP,IBRPP,IBRSP,IBDIAG,IBXTRC,IBRDI,IBWRTI,IBRDIA,IBWRTIA,
IBSTA%,IBERR%,IBCNT%)
70 TEMP$=”93C” '93C is IEEE address label set up when running IBCONF
80 CALL IBFIND(TEMP$,TEMP'%)
'Required command to address 93C
90 OPEN “A:PROGRAM1” FOR INPUT AS #1
'Open file to get data
100 FOR I=1 TO 10
'Program Steps #01 TO #10
110 INPUT#l,C$
120 B$="E”+ $
'Assemble command
'Add CR and LF to command
130 B$=B$+CHR$ (13)+CHR$ (10)
'Send data to 93C
140 CALL IBWRT(TEMP%,B$)
150 FOR Z=1 TO 1000
160 NEXT Z
170 NEXT I
180 CLOSE 1
190 END
10
20
30
40
50
4.12.3.5
‘
I
I
I
‘
‘
1
National Instruments QUICK BASIC IBM Example of WEN1N2 Request
Quick Basic 3.0 Example #2
THIS PROGRAM WAS WRITTEN FOR THE NATIONAL INSTRUMENTS GPIP-PC2
IEEE-488 CARD FOR IBM PC AND COMPATIBLES
This program will store Programs Step # 1 thru 10 in File “PROGRAM1”
on Disk A:
4-26
COMMON SHARED IBSTA%, IBERR%, IBCNT%
TEMP$=”dev”
“
'93C
'Required to address instrument
CALL IBFIND(TEMP$,TEMP%)
OPEN “A:PROGRAM1” FOR OUTPUT AS #1 'Open file to store data
'Program Steps #01 Thru #10
FOR I=1 TO 10
IF I<10 THEN
Nl$="0”
N2$=LTRIM$(RTRIM$(STR$(I)) )
ELSE
N$=RTRIM$(LTRIM$ ( STR$ ( I)) )
Nl$=LEFT$ (N$,1)
N2$=RIGHT$(N$,2)
N2$=RIGHT$ (STR$(I),1)
END IF
COPYRIGHT 3/88 LSCI
Model DRc-93c
Section IV
B$=”WE"+N1$+N2$
'Assemble command
B$=B$+CHR$ (13)+CHR$ (10)
'Add CR and LF to command
CALL IBWRT(TEMP%,B$)
'Request Program Step I
CALL IBRD(TEMP%,A$)
'Get Program Step I
PRINT A$
'Display received information on screen
PRINT #1,A$
'Save on disk in file PROGRAM1
NEXT I
CLOSE 1
'Close the file
END
4.12.3.6
National Instruments QUICK BASIC IBM Example of E Command
Quick Basic 3.0 Example #3
THIS PROGRAM WAS WRITTEN FOR THE NATIONAL INSTRUMENTS GPIP-PC2
IEEE-488 CARD FOR IBM PC AND COMPATIBLES
This program will restore Programs Step # 1 thru 10 from File “PROGRAM1”
on Disk A:
COMMON SHARED IBSTA%, IBERR%, IBCNT%
TEMP$="dev12“
'93C
'address instrument
CALL IBFIND(TEMP$,TEMP%)
OPEN "A:PROGRAM1” FOR INPUT AS #1 'Open file with data
'Program steps #01 Thru #10
FOR I=1 TO 10
'Get data from file “PROGRAM1”
INPUT #1,C$
B$=”E”+C$
'Assemble command
'Add CR and LF to command
B$=B$+CHR$ (13)+CHR$(10)
'Send command to instrument
CALL IBWRT(TEMP%,B$)
FOR Z=1 TO 1000: NEXT Z
NEXT I
CLOSE 1
'Close the file
END
COPYRIGHT 3/88 LSCI
4-27
4-13 COMMAND OPERATIONS
The following example in HP Basic
sets the set point to 123.4 K, the
gain to 45, the reset (integral) to
30, the rate (derivative) to 25,
the heater range to 10-1 and the
output statement sent to be W3.
If the user were to monitor the
IEEE-488 Bus when the computer sent
its command string over the Bus,
the following IEEE-488 Format would
be observed.
? L
, S123.4P45130D25R4W3(CR)
(LF)
The Universal Unlisten Command (?)
is sent so that no
other
instruments on the Bus will
eavesdrop on the Bus and assume
that the data being sent is for
their attention.
The DRC-93C1s
Talk Address
(L) is sent to
unaddress any existing TALKER.
Note that the BUS CONTROLLER could
have designated another instrument
as the TALKER. Therefore, to keep
the format consistent, it must send
a Talk Address even when the DRC93C is going to be that TALKER.
The Listen Address (,) must be sent
to tell which instrument on the Bus
is to receive the Data String.
Note that [TERM1][TERM2] have been
indicated to be CR LF (carriage
return, line feed) ;
these are the
correct terminators for the HP
computer example.
Note that the string “P45130P40”
would result in a gain of 40 and an
integral value of 30, i.e., only
the last value sent over the bus
for that command will be entered
after the appropriate terminators
have been sent over the bus.
4-28
4-14 OUTPUT DATA STATEMENTS
The DRC-93C1s Output Requests for
Data Statements are summarized in
Table 4-5.
The DRC-93C will always respond
when asked to talk with the last
command sent to it, i.e. , if WO is
sent once then the 93C will always
output the WO information whenever
it is asked to talk as long as it
has not received another output
data statement.
4.14.1
The “WS", “WC" and “WP” Data
Strings
These three commands are subsets of
the “WO” command: the “WS” command
giving the Sample Sensor reading,
the “WC” command the control sensor
reading while the “WP” command
results in the set point value.
4.14.2
The “WO" Data
String
The following example in HP Basic
illustrate the commands associated
with obtaining output data from the
DRC-93C.
The addition of the MO
command returns the instrument to
front panel control where it stays
even when data is requested from
the 93C by the HP computer.
10
DIM A$ [19]
20
OUTPUT 712; “WOMO”
30
ENTER
712;A$
The following information is sent
across the bus in the IEEE-488
format as a result of the above
software commands.
Request sent:
? U , W 0 M 0 (CR)(LF)
Data returned:
The data above indicates that the
COPYRIGHT 3/88 LSCI
Model DRc-93C
display temperature is 123.45K and
that the set point is 123.40K.
T a b l e 4-15.
Request
ws
wc
WP
wo
Section IV
DRC-93C Output Data Statements
Output of Instrument Data
Sample Sensor Data
8 Characters plus up to 2 Terminators where the
variations are the same as for WO (see below).
Control Sensor Data
8 Characters plus up to 2 terminators where the
variations are the same as for WO (see below).
Set Point Data
8 Characters plus up to 2 terminators where the
variations are the same as for WO (see below).
Sample (WS), Control Sensor (WC) and Set Point (WP) Data
26 characters plus up to 2 terminators where:
WM
Display Math Data
57 characters plus up to 2 terminators where:
COPYRIGHT 3/88 LSCI
4-29
Section IV
Model DRc-93C
4-15SAMPLE PROGRAMMING
4.15.1 HP86B Keyboard Interactive Program
The following program for the HP86B is an interactive program with the
keyboard of the computer. For example, when the user sees the prompt on
the screen and types in a valid DRC-93C command such as “WO”, the program
will result in the display of the DRC-93C response on the screen.
10 REM Set IEEE Address to 12
20 REM Address Switch 1 OPEN(0) to get (CR)(LF)
30 REM This program allows the user to communicate with the 93C,
interactively from the computer keyboard
DIM A$[100]
! Must be increased for curve information
INPUT B$
! INPUT KEYBOARD COMMAND
OUTPUT 712 ;B$
! SEND COMMAND TO 93C
ENTER 712 ;
A$
! RECEIVE ANSWER FROM 93C
DISP A$
! DISPLAY ANSWER
40
50
60
70
80
90
GOTO 50
100 END
4.15.2 National Instruments GWBASIC or BASICA IBM Example
The following is the same program written for the National Instruments
GPIP-PC2 IEEE-488 Card for IBM PCs and Compatibles using Quick Basic 3.0.
10 CLEAR
,60969 ! BASIC DECLARATIONS
20 IBINITl = 60969 ! This number is different for each computer
30 IBINIT2 = IBINITl + 3
40 BLOAD "bib.m”,IBINITl
50 CALL IBINIT1(IBFIND,IBTRG,IBCLR,IBPCT,IBSIC,IBLOC,IBPPC,IBBNA,IBONL,
IBRSC,IBSRE,IBRSV,IPPAD,IBSAD,IBIST,IBDMA,IBEOS,IBTMO,IBEOT,IBRDF,IBWRTF)
60 CALL IBINT2(IBGTS,IBCAC,IBWAIT,IBPOKE,IBWRT,IBWRTA,IBCMD,IBCMDA,IBRD-
,IBRDA,IBSTOP,IBRPP,IBRSP,IBDIAG,IBSTRC,IBRDI,IBWRTI,IRDIA,IBWRTIA,
IBSTA%,IBERR%,IBCNT%)
70 TEMp$=”93C” ! 93C is IEEE address label set up when running IBCONF
80 CALL IBFIND(TEMP$,TEMP%) ! Required command to address 93C
90 A$=SPACE$(255)
! 255 largest data transfer allowed by IBM format
! Entered from keyboard while running
100 INPUT B$
110 B$=B$+CHR$(l3)+CHR$(10) ! Add CR and LF to command
120 CALL IBWRT(TEMP%,B$)
! Send command to 93C
130 CALL IBRD(TEMP%,A$)
! ENTER from 93C (SEE NOTE BELOW)
140 PRINT A$
! Display received information on screen
150 A$=SPACE$(255)
! Clear A$
160 GOTO 110
170 END
180 REM The 93C will return data requested, but if the command input
does
190 REM not request new information, the 93C will give the information
last requested.
4-30
COPYRIGHT 3/88 LSCI
Section IV
Model DRC-93C
4.15.3
National Instruments
QUICK BASIC
IBM Example
IEEE-488 TEST PROGRAM Quick Basic 3.0 Example
THIS PROGRAM WAS WRITTEN FOR THE NATIONAL INSTRUMENTS GPIP-PC2
IEEE-488 CARD FOR IBM PC AND COMPATIBLES
This program will allow the user to communicate with Lake Shore's
instruments, interactively from the keyboard of an IBM compatible
computer which has a National Instruments GPIB-PC2 installed.
common shared IBSTA%, IBERR%, IBCNT%
print “Input number for the type of instrument---820,93C,82C, or 93C
print “0=820”
print "2=82C”
print “1=93C”
print 3=93C"
input I$
if I$=”0” then TEMP$=”dev20” 'default address for 820
if I$=”1” then TEMP$=”dev12” 'default address for 93C,etc.
if I$=”2” then TEMP$=”dev12”
if 1$=”3” then TEMP$=”dev12”
'set up when running IBCONF
'Required command to address instrument
call IBFIND(TEMP$, TEMP%)
A$=space$( 750)
Loopl: input B$
B$=B$+chr$(13)+chr$ (10)
call IBWRT(TEMP%,B$)
call IBRD(TEMP%,A$)
print A$
A$=space$ (750)
goto Loopl
'Entered from keyboard while running
'Add CR and LF to command
'Send command to instrument
'ENTER from instrument (SEE NOTE BELOW)
'Display received information on screen
Clear A$
end
Lake Shore Cryotronics instruments will return the data requested,
but if the command input to the instrument does not request any
information the instrument will respond with the information last
requested.
4.15.4
HP86B Bus Commands Program
The following program is for the HP86B and exercises the various bus
commands.
10 REM Set IEEE Address to 12
20 REM Address Switch 1 OPEN (0) to get (CR) (LF)
30 DIM A$[42]
! For longest string
40 OUTPUT 712;”W0”
! Note WO
50 ENTER 712;A$
! Ask for string WO
60 DISP "WO = “;A$
! Display string WO
! Display Sensor reading
70 DISP "Display Sensor =” ;A$[ 1,8]
! Display Control Sensor Reading
80 DISP “Control Sensor =” ;A$[ 10,171
90 DISP “Set Point =";A$[19,26]
! Display Set Point Reading
COPYRIGHT 3/88 LSCI
4-31
Section IV
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
330
340
350
360
370
380
390
400
410
420
430
440
450
460
470
Model DRC-93C
DISP
OUTPUT 712;”W1”
ENTER 712;A$
DISP "W1 = “;A$
DISP
OUTPUT 712;”W2”
ENTER 712;A$
DISP "W2 = “;A$
DISP
OUTPUT 712;”W3”
ENTER 712;A$
DISP “W3 = ";A$
DISP "Gain =”;A$[1,3]
DISP “Rate =”;A$[5,7]
DISP “Reset =”;A$[9,11]
DISP " H e a t e r R a n g e =";A$[13]
DISP “% Power =”;A$[15,17]
DISP
OUTPUT 712;”WS”
ENTER 712;A$
DISP “WS = ";A$
DISP
OUTPUT 712;”WC”
ENTER 712;A$
DISP "WC = ";A$
DISP
OUTPUT 712;”WP”
ENTER 712;A$
DISP “WP = “;A$
DISP
OUTPUT 712;”WY”
ENTER 712;A$
DISP “WY = “;A$
DISP
OUTPUT 712;”WI”
ENTER 712;A$
DISP “WI = ";A$
END
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
4.16 SENSOR CURVE PROGRAMMING
INSTRUCTIONS
The commands which w i l l either
output, input, e d i t o r erase a
Sensor Curve are given i n T a b l e
4-16.
I n a d d i t i o n , the commands t o
assign o r change assignments of the
various curves t o t h e Sensor I D
t a b l e s (both A and B) are given i n
Table 4-16.
4.16.1
The XDT Command
This
command
4-32
from
the
BUS
! Space a Line
A and B Input information
Ask for s t r i n g W 1
Display s t r i n g W 1
Space a Line
Interface Status
Ask for s t r i n g W 2
Display s t r i n g W 2
Space a Line
Control D a t a (Gain, R e s e t , etc.)
Ask for s t r i n g W
3
Display s t r i n g W 3
Display Gain s e t t i n g
Display R a t e s e t t i n g
Display R e s e t s e t t i n g
Heater Range
% Power
Space a Line
Set f o r W
S
Ask f o r s t r i n g W
S
Display Sensor Reading
Space a Line
S e t f o r WC
Ask for s t r i n g WC
Display Control Sensor Reading
Space a Line
Set f o r W P
Ask f o r set p o i n t d a t a
Display s t r i n g WP
Space a Line
S e t for WY
Ask for Scan Information
Display Scan Information
Space a Line
Set f o r W I
Ask Input Cards and Options
Display s t r i n g W I
CONTROLLER t e l l s t h e DRC-93C t h a t
when it is asked t o output d a t a ,
t h a t data should be the output of
the standard Sensor Curves s t o r e d ,
Precision Option Curves s t o r e d and
the format associated w i t h t h e
REMOTE SENSOR I D Remote Position t o
Sensor Curve assignments as given
i n T a b l e 4-17.
This output is
defined as the Sensor Curve Information T a b l e (SCIT)
As can be
seen from the output shown on this
page, t h e instrument is shipped
with a l l remote p o s i t i o n s c a l l i n g
up Standard Curve 02.
.
COPYRIGHT 3/88 LSCI
Model DRC-93c
The information lines for Sensor
Curves 05 through 31 will only be
present if these curves are
actually present either as user
generated curves or as Precision
option curves.
The Information
Table is output as one very lonq
character string.
The following program is for the
HP86B and is an example of the XDT
output (SCIT) for a unit with only
Standard Curves 00 thru 05 present.
10 REM Program to Output SCIT
20 DIM FILETABLE$[321]
30 OUTPUT 712;”XDT”
!Ask for
40 ENTER 712;FILETABLE$ !Input SCIT
50 DISP FILETABLE$[1,16]!Bytes Free
60 DISP FILETABLE$[17,38] !Next Loc
70 DISP FILETABLE$[39,56] !Curve 00
80 DISP FILETABLE$[57,74] !Curve 01
90 DISP FILETABLE$[75,92] !Curve 02
100 DISP FILETABLE$[ 93,1101!Curve
03
110 DISP FILETABLE$[111,128]!Curve
04
110 DISP FILETABLE$[129,152] !A00
120 DISP FILETABLE$[ 153,1761
130 DISP FILETABLE?,$[177,200]
140 DISP FILETABLE$[201,224]
!Thru A1F
150 DISP FILETABLE$[225,248] !BOO
160 DISP FILETABLE$[249,272]
170 DISP FILETABLE$[273,296]
180 DISP FILETABLE$[297,319]
!thru B1F
190 END
Note that the last character to be
displayed is number 319 since the
Terminators (CR)(LF) have to be
input but not displayed.
This
program results in the following
output of the Sensor Curve
Information Table.
05,31,20BO,RESVRD,
Section IV
02,02,02,02,02,02,02,02,
02,02,02,02,02,02,02,02,
02,02,02,02,02,02,02,02,
02,02,02,02,02,02,02,02,
02,02,02,02,02,02,02,02,
02,02,02,02,02,02,02,02,
02,02,02,02,02,02,02,02,
02,02,02,02,02,02,02,02
4.16.2
The XIN1N2 Command
The XDN1N2 command is used to
output a particular Sensor Curve
(rather than all the curves stored
within the instrument as in the XDA
command) with N1N2 being the curve
number 00 thru 31. The format of
the Sensor Curve output is given in
Table 4-18.
The information is
output as one very long character
string.
The following program is
for the HP86B and is an example of
the XDN1N2 to output Sensor Curve
00.
10 REM
Program to output Curve
Table
20 DIM Curve$[462]
30 OUTPUT 720;”XD00”
40 ENTER 720;Curves
50 REM Display Curve #, Title,
Temperature
60 REM Coefficient and Number of
Breakpoints 70 DISP Curve$[1,27]
80 REM Display voltage and temp
data points
90 I=28
100 DISP Curve$[I,I+41] ! Voltage;
Temp.
110 IF I=447 THEN 140 ! I=477 for
D.Pnt 31
120
130
140
150
I=I+42
GOTO 100
DISP Curve$ [448,460]
END
3584 BYTES FREE,
0200 IS NEXT LOCATION,
00,31,1D40,DRC-D ,
01,31,lDFO,DRC-E1,
02,31,1EAO,CRV 10,
03,31,1F50,DIN-PT,
04,31,2000,cRV 10,
COPYRIGHT 3/88 LSCI
4-33
Section IV
Table 4-16.
Model DRC-93C
Sensor Curve Commands and Description
Output of Information Table, Sensor Curve or All Curves
Commands
Output the Sensor Curve Information Table. Refer
to Table 4-17 for the format of the output.
XDT
XDN1N2
Output Sensor Curve number N1N2 where N1N2 is from
00 to 31. Refer to Table 4-18 for the format of the
Sensor Curve output.
XDA
Output the Sensor Curve Information Table (XDT) and
all the Sensor Curves stored in the unit. Refer to
Table 4-17 for format of the Information Table output
and Table 4-18 for format of the Sensor Curve output.
Curve Input, Curve Edit and Curve Erasure
Sensor Curve Input. N1N2 is Sensor Curve number from
,
C1....C18,
06 to 31. Immediately after Sensor Curve cmmnd XCN1N2
X.XXXXX,TTT'.T, a comma is required. Up to 18 characters can be input
as a curve description. When all 18 characters are
input, the last 6 are used in the Sensor Curve table
(in the 8000 Series Precision Option curves these 6
characters are used to indicate the sensor serial no.)
The 18 characters must be immediately followed by a
comma. The data is input in units/temperature pairs
with the units in the form of Voltage, Requiv or LogR.
Data points must be entered in ascending units order.
*
The * character terminates the Sensor Curve input.
Edit Sensor Curve N1N2. The point is either inserted
XEN1N2,
X.XXXXX,TTT.T* in its proper position in the curve or it is added to
the curve as a new data point.
XKN1N2*
Erases (kills) Sensor Curve N1N2 and repacks all curve
data (Standard Curves 00 thru 05 cannot be erased).
XR&I*
Command sent five times will delete all Precision
Options and any curves stored in unit by user.
Assignment of Curve # to Position # in Correlation Tables
*
Assign the Input A or Input B Remote Position
to
Sensor Curve number
C1C2 is the Remote Position
00 thru 1F. N1N2 is the Sensor Curve number 00 thru 31
This Command modifies the Remote Position to Sensor
Curve Correlation Table 3-3 (and XDT output data).
NOTE: The * added to the end of the
xBC1C2, XCN1N2, XEN1N2 and
XK commands is required for the command to operate properly. Due to the
length of some of the data strings, appropriate computer time outs must
be allowed when performing these functions. If a hardware problem is
detected in modifying one of the NOVRAM locations, an Err01 error will
be displayed and instrument operation is halted. An Err02 error is
displayed if the unit detects a NOVRAM hardware problem.
4-34
COPYRIGHT 3/88 LSCI
Section IV
Model DRC-93c
T a b l e 4-17.
Command
Sensor Curve Information T a b l e OutputFormat
output
XDT
minimum of 321 Characters (when only the 6 Standard Curves
are present) and a maximum of 805 Characters (when all 32
Curves are present) plus up to 2 Terminators where:
is the decimal number of curve locations
available (BYTES FREE).
is the Hex address the next curve will start at.
is the Sensor Curve assigned to Remote Position
A00 through A1F and BOO through B1F.
A
T a b l e 4-18.
Command
XDN1N2
Sensor Curve Output Format
output
minimum of 54 Characters (for a curve with the minimum of
data points) and a maximum of 1412 Characters (for a curve
the maximum of 97 data points) plus up to 2 Terminators where:
is the Sensor Curve number 00 thru 31.
is the 18 Character Information line.
is the Temperature Coefficient, P or N.
is the number of data points 00 thru 99.
is the Voltage, Equivalent V or Log R.
is the Temperature to 0 . 1 only.
A
2
COPYRIGHT 3/88 LSCI
4-35
Section IV
Model DRC-93C
Note that the last character to be
displayed is number 460 since the
Terminators (CR)(LF) have to be
input but not displayed.
This
results in the following display.
The N indicates that the silicon
diode is a negative temperature
coefficient device.
For the
platinum curve (03), which is a
positive temperature coefficient
device, a P will appear in that
position.
command are 06 thru 31 (note that
the first five curves 00 thru 04
are the Standard Curves with \
05 reserved)
The format for the
XC command is given in Table 4-16.
The format for the XC command must
be followed for the curve entry to
be successful.
Following the
XCN1N2 (where N1N2 is between 06
and 31) is a comma. Then up to 18
characters can be entered as a
curve information line. At least
one character is required and any
more than 18 characters are
ignored.
If 18
characters are
input, the last 6 are used in the
Sensor Curve Information Table as a
capsule description of the curve
(in the 8000 Series Precision
Option curves these 6 characters
are used to indicate the sensor
serial number). The 18 characters
must be immediately followed by a
comma.
The data points are then
input in the form X.xXXXX, comma,
TTT.T.
The X.xXXXX input is in
Voltage or LogR.
Refer to Table
4-19 for the conversion of the raw
units information into the format
required for the XC command. The
unit automatically fills in leading
and trailing zeroes in the data
point.
A data point entered as
0.8,70,
would be converted
b y
t h e
u n i t
into
4.16.3 The XDA Command
The XDA command asks for the output
of the Sensor Curve Information
Table as well as all the Sensor
Curves stored in the unit. When
the command XDA is used, the 93C
will output the Information Table
formatted as in Table 4-17 followed
by a comma (in place of the
Terminators) followed by each
Sensor Curve in ascending order
with a comma between each Sensor
Curve (in place of the Terminators)
as in Table 4-18 until all the
curves have been output followed by
the Terminators. The information
is output as one very lonq
character string.
4.16.4 The
XCN1N2
Command
The XCN1N2 command is the most
powerful curve command in the 93C.
It allows for the remote input of
Sensor Curves. The Sensor Curves
that can be input using the XC
4-36
.
...,
...
COPYRIGHT 3/88 LSCI
Model DRC-93C
...,
... .
0.80000,070.0,
The data
points must be entered in ascending
u n i t s order.
After all the data
points are entered the ( * )
character terminates the Sensor
Curve input.
Following the input of the (*) to
indicate to the unit that the there
are no more data points, it
determines and stores whether the
curve is a positive or negative
temperature coefficient curve.
Based on temperature coefficient,
the unit then stores the curve end
points. For a negative temperature
coefficient curve the first end
point is 0.00000,499.9 and the last
end point is 6.55360,000.0. For a
positive temperature coefficient
curve the first end point is
0.00000,000.0 and the last end
point is 6.55360,999.9. Therefore,
the minimum number of data points
which the user can input for a
curve is 1 (which would result in a
3 data point curve) and the maximum
number of data points is 97 (which
would result in a 99 point curve).
The XC information must be output
to the unit as one very lonq
character String.
The first character of the 18
character management
string
indicates the type of breakpoints
to be entered. If the character is
an "L", then the unit performs
Lagrangian calculations on the
data. If the character is anything
else, the unit performs Straight-Line interpolation on the data.
See Appendix B for a description of
the difference between the two. In
addition,
s e n s o r type and
temperature range is included in
this 18 characters as well.
Curves 06 thru 31 are stored in
Non-Volatile RAM (NOVRAM)
where
the first 0200 hex bytes are
reserved for file management.
COPYRIGHT 3/88 LSCI
section IV
There are 3584 bytes free for the
storage of curves.
If the curve
stored has 31 data points, it will
take up 177 bytes. For this length
curve, up to 20 curves can be
stored in the unit.
Refer to
Appendix B for additional information on curve entry and how the
curves are generated.
4.16.5
The XEN1N2 Command
The command
either adds a point to or edits the
N1N2 curve (provided that this
curve is present).
The *
terminates the data point input.
If either the units or temperature
information matches one of the data
points in the curve the curve data
point edited to match the XE data
point If the information does not
match any of the data points for
the curve, the unit inserts the
point in its proper position in the
table.
4.16.6
The
Command
The command XKN1N2* erases all the
data associated with curve number
N1N2 and repacks the remaining
curves stored within the NOVRAM.
Standard Curves 00 thru 05 are
stored in a Prom and are not
erasable by this command.
The XA an XB commands allows Table
3-4 which defines the correlation
between the Remote Position and
Sensor
Curves
for
the
R E M O T E S E N S O R ID. Notethat this correlation exists for
both inputs and normally only one
input would select the REMOTE
SENSOR ID position data. Once this
data has been changed, it would be
good practice to read out the
changed table by means of the XDT
4-37
Section IV
Model DRC-93c
command and update Table 3-4. C1C2
is the hex Remote Position, 00 t h r u
lF, and N1N2 is the decimal curve
number 00 thru 31.
Table 4-19.
Input Card
Conversion of Raw U n i t s Data for the
Units
9210/20-3 Voltage
9210/2 0-6
9215
9317C
9318C
Conversion
Input range is 0.00000 to 6.55350 volts.
No conversion is necessary.
Capacitance No conversion to temperature is allowed
Resistance
9220-P2
Resistance
9220-P3
Resistance
9220-R1
Resistance
4-38
XC Command
In ut range is 1 to 104
for the 9317C, 1 to
10 n for the 9318C. Input must be in Log R
where 1 would look like 0.00000 and 105
would look like 5.00000.
Input range is 0.00 to 299.99 ohms. 0.00 ohms
looks like 0.00000 and 299.99 ohms looks like
2.99990 (0.01 times R)
.
Input range is 0.0 to 2999.9 ohms. 0.0 ohms
looks like 0.00000 and 2999.9 ohms looks like
2.99990 (0.001 times R).
Input range is 0.00 to 100.00 ohms. 0.00 ohms
looks like 0.00000 and 100.00 ohms looks like
3.00000 (0.03 times R).
COPYRIGHT 3/88 LSCI
S E C T I O N
V
M A I N T E N A N C E
5.1 INTRODUCTION
This section contains information
necessary to maintain the Model
DRC-93C. General maintenance, fuse
replacement, line voltage selection
and performance testing is contained in this section.
5.2
GENERAL MAINTENANCE
Clean the DRC-93C periodically to
remove dust, grease and other contaminants. Use the following procedure:
1. Clean the front and back panels
and case with a soft cloth dampened with a mild detergent and
water solution.
Note :
DO NOT use aromatic
hydrocarbons or chlorinated solvents to clean the DRC-93C. They
may react with the plastic materials used in the unit or the silk
screen printing on the back panel.
2. Clean the surface of the printed
circuit boards (PCB) using
clean, dry air at low pressure.
If grease is encountered, spray
with Freon T.F. degreaser and
remove grime with dry, low-pressure air.
5.3
FUSE REPLACEMENT
The line fuse is accessible from
the rear of the DRC-93C. Use the
following procedure to check and/or
replace the fuse:
COPYRIGHT 3/88
WARNING
To prevent shock hazard, turn
off instrument and disconnect
it from AC line power and all
test equipment before replacing
the fuse.
1. Set the POWER switch to OFF and
disconnect the power cord from
the unit. The fuse compartment
is located just to the right of
the power connector.
2. Open
the fuse compartment by
prying open the cover with a
small screw driver.
3. Remove the lower fuse holder by
sliding it out of its position
with the aid of the small screw
driver.
CAUTION
For continued protection against
fire hazard, replace only with
the same type and rating of fuse
as specified for the line
for the line voltage selected.
4. Replace the fuse per Table 2-1.
5. Replace fuse holder, close fuse
compartment and
cord.
5.4
connect power
LINE VOLTAGE SELECTION
The rear-panel, three-pronged line
power connector permits the DRC93C to be connected to 100, 120,
220, or 240 VAC line voltages. Use
the following procedure to change
the line voltage:
5-1
section V
WARNING
To prevent shock hazard, turn off
the instrument and disconnect it
from AC line power and all test
equipment before changing the
line voltage selection.
1. Pull
fuse compartment cover
using the procedure found in
Section 5.3.
2. Remove
voltage selector wheel
and insert with the proper voltage facing out. Note that the
wheel can only be inserted with
the writing read from the left.
3. Install the proper fuse as out-
lined in Section 5.3.
5.5
OPERATIONAL
5.5.1
CHECKS
Test Connector
J1 INPUT A or J2 INPUT B connector
to simulate a diode sensor input is
required for operational checks of
the DRC-93C.
The test connector
can be made by taking one of the
plugs supplied with the DRC-93C and
configuring a resistor to simulate
the temperature sensor in the two
wire configuration as described in
Section 2.3.6.
The test resistors
specified in Table 5-1 are used in
the operational checks.
Operational T e s t
procedure
The operational test procedure is
designed to verify the overall
operation of the DRC-93C and can be
used as a periodic maintenance
check. The following equipment is
used in the test.
Voltmeter resolution or better.
1. Digital
5-2
Section 5.5.1.
4½ digit
-
fabricated per
Complete the following
procedure for this test:
set-up
1. Plug the connector into INPUT A.
2. Connect the DVM across the test
resistor of Input A.
3. Connect
the DRC-93C to line
power and turn the unit ON.
Verify that the DRC-93C initializes to the proper POWER-ON
state as defined in Section 3.7.
The following procedure is used to
test the overall DRC-93C operation.
Note: The unit should be allowed a
one-hour warm-up time to achieve
rated specifications.
5.5.3
A test connector for the rear panel
5.5.2
2. Test Connector
Model DRC-93c
Current
source
Check
The DVM across the test resistor
should read as follows:
9210/20-3
9210/20-6
9220-P2
9220-P3
9220-R1
9317C
9318C
5.5.4
1.0000V ± 100µV
1.0000V ± 100µV
0.10000v ± 10µV
0.10000v ± 10µV
0.03000V ± 10µV
N/A
N/A
Monitor Voltage
The voltage across the sensor or
test resistor is also available on
the monitor plug. The connections
are given in Section II of this
manual.
The monitor voltage will
be equal to the sensor voltage for
3 volt (-3) diode inputs and all
platinum (-P2, -P3) and rhodium
iron (-R1) inputs. If the input is
a GaAlAs Diode (-6) input then the
monitor voltage will be 0.458 times
the sensor voltage.
This test is
not applicable for the 9215, 9305,
9317C or 9318C input cards.
COPYRIGHT 3/88 LSCI
Model DRC-93C
5.5.5
Temperature Display
5.5.5.1
Determine Input--The
first step to check the instrument's display and operation is to
determine the type of sensor input.
a. The type of input option card(s)
installed in the DRC-93C is
located on the front page of
every DRC-93C manual.
b. The DRC-93C displays the type of
input card(s) installed in the A
and B inputs sequentially when
the instrument is powered on.
Possibilities are 9210-3, 92106, 9215-30, 9215-150, 9220-3,
9220-6, 9220-P2, 9220-P3, 9220R1, 9305, 9317C or 9318C.
Section V
a. Check the Sensor Curve Table
(Table 3-2 or below) to determine the curve number that
selects the standard curve or
precision option that is needed.
A 9215 card will not read temperature.
The 9317C/9318C will
not read accurately in temperature unless a precision
option is present.
b. Select the curve as described in
Section 3-9.
c. The type of input can also be
displayed by holding down the
SENSOR key.
5.5.5.2
check units displayVerify that the A units can be
changed by holding in the UNITS key
and using the
or the
to
scroll through the sequence K, C,
F, V, K, etc. (Note: the unit goes
to V for a diode configuration
9210-3, -6 or 9220-3, -6) or
for
a resistance card configuration
(9220-P2, -P3, -R1 or 9317C/ 9318C
Input card).
5.5.5.3
check sensor u n i t s reading
Next, check to see if the instrument is reading the correct sensor
units (volts, ohms or nanofarads)
value for the appropriate test
resistor or capacitor from Table
5.1.
The reading should match the
value given in the Display in Sensor Units column of Table 5-1. The
allowable error is provided in the
Input A/D Accuracy column.
Check temperature reading5.5.5.4
Confirm that the temperature in
kelvin displayed corresponds to the
selected curve number.
COPYRIGHT 3/88
-
5.5.5.5
Check Input B
Change the
connector from J1 INPUT A to J2
INPUT B. Repeat the above process
by verifying the current source and
the A/D settings for this input as
well as the units change.
5.5.6
Heater O u t p u t Test
H e a t e r Output Conditions5.5.6.1
The heater should output power when
the setpoint temperature is above
the display temperature, as long as
the heater is on and a gain value
has been entered. If the sensor is
a diode, the voltage across the
device will change inversely with
temperature. Therefore the higher
the voltage the lower the temperature.
For Platinum sensors the
resistance increases as the temperature increases.
Germanium and
carbon glass sensors are negative
temperature coefficient resistance
sensors which vary several orders
of magnitude in resistance with
temperature.
5-3
Section V
5.5.6.2
Test Setup - T e s t the heater by placing an appropriate test
r e s i s t o r (see T a b l e 1) i n t o the
control sensor input, and place a
1 0 ohm ( a t least 1 0 watts) up t o 50
ohm ( a t least 50 watts) r e s i s t o r
across the heater terminals.
-
5.5.6.3.
The Heater Display
The
heater display is shipped from the
factory reading the percent of
power out.
I f the heater is 1 0
ohms then a t 100 percent output
current, the heater w i l l have 1 amp
through it and 1 0 v o l t s across it.
I f the heater bar graph is reading
50% then the instrument is delivering 5 w a t t s (0.707 amps and 7.07
v o l t s ) t o the 1 0 ohm load. I f the
u n i t is reading i n current a reading of 50 w i l l mean 2.5 w a t t s (0.5
amps and 5 v o l t s ) . The heater display can be changed from power t o
current by switching internal d i p
s w i t c h S4-1.
5.5.7
Checking Gain, R e s e t and Rate
Check the operation of the Gain,
Rate and R e s e t as follows:
a dummy load i n t o the
selected sensor input.
a. 5 0 K t o 100K f o r a diode.
b. Short V+ t o V- f o r 9317C o r
9318C Input Card.
c. 10nF capacitor f o r 9215 Input
1. Place
Card.
a 10 ohm, 10 w a t t (or
greater) resistance load on the
heater terminals.
2. Place
the Display Units t o Sensor
Units, i.e., v o l t s , ohms o r
nanofarads.
a. I f 9210-3/20-3 e n t e r a v o l t
age 0.01 v o l t s less than the
display.
b. I f 9317C o r 9318C, e n t e r a
resistance of 1 ohm f o r the
set point.
c. I f 9215 e n t e r 11nF set point.
3. S e t
5-4
-
Model DRC-93C
5.5.7.1.
Gain
Enter a gain value.
The heater display should now indicate that power is being delivered
t o the heater. The amount of power
is a scaled f a c t o r of the e r r o r
signal times the gain ( [Sensor
-
voltage
Setpoint voltage] *
Gain). I f the setpoint temperature
is increased o r the gain is increased the output power w i l l increase.
Keep the LO lead of the DVM a t TP1
and move the H I lead t o TP29. Turn
off the G A I N , RATE and RESET by
entering a value of 0.0 f o r each.
The DVM w i l l now read approximately
0.0 v o l t s .
Change the GAIN t o 1.0
and the DVM w i l l read approximately
0.1 v o l t s which is the e r r o r O f
0.01 times the gain of 10.
Change
the GAIN t o 1 0 and the DVM w i l l
read approximately 1 v o l t . Setting
the GAIN t o 99 w i l l r e s u l t i n a
reading of approximately 7.2 v o l t s .
Reset - Set up the conas instructed i n s t e p
5.5.6.1.
Enter a gain and setpoint
value that r e s u l t s i n less than
f u l l power t o the load. I f a R e s e t
value is now entered, the instrument w i l l t r y t o integrate out the
error. W i t h a test r e s i s t o r i n the
control sensor input and a fixed
setpoint, the e r r o r signal w i l l be
constant.
W i t h a constant e r r o r
the R e s e t w i l l continue t o increase
the analog output control signal
u n t i l the heater display reads 100
percent. If the heater output increases t o approximately 100 percent f o r these conditions the reset
c i r c u i t is operating.
5.5.7.2
troller
To check the RESET c i r c u i t i n more
d e t a i l use the same set point and a
GAIN of 10.
Move the H I lead of
the DVM t o TP30 and e n t e r a RESET
of 1.0.
The reading on the DVM
should gradually i n t e g r a t e t o approximately 7.2 v o l t s .
The time
required w i l l depend on the amount
COPYRIGHT 3/88 LSCI
section V
Model DRC-93c
of reset with time required being
the shortest for higher settings.
Next, turn the reset off and make
sure that the reading returns to
0.0 volts.
-
5.5.7.3
Rate The operation of the
Rate can not be observed without
measuring voltages in the unit.
To check the RATE move the DVM HI
lead to TP31, keep the GAIN at 10,
turn the RESET off (0.0) and enter
a RATE to 99. The DVM should read
0.0 volts.
Quickly change the set
point value from approximately
equal to the display value to a
value 20% higher in equivalent
kelvin temperature, e.g. from 1.00
volts to 0.80 volts.
The DVM
should show a positive transient
whose peak value will lie between
0.1 and 7 volts depending on the
rate at which you change the set
point, the amount of gain, the
speed at which you change the voltage as well as when the reading is
read by the DVM.
For the change
from .80 to 1.00 the reading will
be negative in value.
The GAIN, RATE and RESET values are
summed together before the heater
drive circuit with the GAIN being
multiplied by two in signal
strength before summation. The sum
of the three terms can be measured
at TP28 ANA OUT.
5.5.8
Checking the H e a t e r Ranges
-
Standard 50 W a t t output
5.5.8.1
Set up the unit so that 100 percent
is output to the heater load. At
full power out on the Max scale 1
amp should be through the resistor,
as long as the resistor is 50 ohms
or less. The heater circuit has a
compliance voltage limit of 50
volts, so a resistor larger than 50
ohms will limit the current to 50
divided by the load's Resistance.
If the next lower range (-1) is
COPYRIGHT 3/88
selected then the heater will put
0.33 amperes through the resistor
at 100 percent. The -2 range will
output 0.10 amperes at full scale
output. At the -3 range the output
will be 0.033 amperes full scale
and at the -4 range the output will
be 0.001 amperes
-
5.5.8.2
W60 W a t t Option
If the
unit has a W60 output option the
Max scale has a 1.55 amp, 40 volt
limit.
If a 25 ohm resistor is
used the controller will supply 60
watts to the load. If a 100 ohm
resistor is used on the M a x scale
the unit will output 40 volts at
0.4 amps or 16 watts.
The lower
ranges are scaled as explained in
5.5.7.1 above except the voltage
limit is 43 volts.
NOTE: The values given above are
nominal values. If they are slightly off it should not effect operation since the heater circuit is
part of a feedback loop.
5.6
CALIBRATION
The adjustments and test points
referred to in this section are labeled on the instrument calibration
cover.
Remove the two top panel
screws and slide the top cover off
to gain access to the adjustments
and test points.
Note: The unit should be allowed a
one-hour warm-up time to achieve
rated specifications.
This Calibration procedure is for a DRC-93C
with standard diode A and B inputs.
For other configurations, refer to
Section VII for the specific Input
C a r d present in the unit.
5.6.1
Input Card Calibration
Calibrate each input card as specified in Section VII for that card.
5-5
section V
5.6.2
Model DRC-93c
Set Point Voltage Calibration
Calibrate the Set Point Voltage as
follows:
1. Remove the instrument cover.
2. Calibrate
with the Control
Switch selecting either a 9210
or 9220 Input Card and the -3
configuration.
If the DRC-93C
does not contain one of these
input cards, calibrate the set
point by following the procedure
described with that Input Card.
3. To calibrate the Set Point volt-
age with a 9210 or 9220 card,
connect the LO lead of your DVM
to TP1 and the HI lead to TP25
SP v.
4. Enter a set point of 0.0000V and
adjust the potentiometer labeled
SP ZERO ADJ until the DVM reads
0.0000 volts.
5. Enter a set point of 2.7000V and
adjust the potentiometer labeled
SP SPAN ADJ until the DVM reads
-2.7000 volts.
6. Repeat
the two settings until
the values are constant.
5.6.4
Calibration of Power Output
If the heater output is not the
standard 50 watts for the DRC-93C,
the optional power output installed
should be indicated on the front
page of this manual.
1. Verify
that
the
back
panel
HEATER RESISTANCE switch is on
10-25 and use a load resistor
between 10 and 25 ohms with a
wattage rating equivalent to its
resistance. The W60 output requires a load between 10 and 25
ohms with a wattage rated 1.5
times the resistance value.
5-6
Set a set point and gain value
which results in full scale output
on the MAX Heater Range scale.
2. With full power across the load
resistor on the -1 scale, place
the DVM LO probe in TP19 PWR V+
and the DVM HI probe in TP21 and
adjust PWR V+ until the DVM
reads 1.000 volts.
There now
should be one ampere through the
load (1.5 amperes in the case of
the W60). The heater can now be
turned off.
3. Place the DVM LO into TP15 PWR
V- and the DVM HI into TP17 HTR
V+ and adjust PWR V- ADJ until
the DVM reads 1.0000 volts.
4. Place the DVM LO into TP20 FWR
LD and the DVM HI into TP16 VREF
and adjust PWR VREF until the
DVM reads 1.0000 volts.
5. Repeat 3 and 4 until they do not
change.
Note: TP 24 CNT V is the control
voltage.
For the 9210/20-3 it is
the voltage across the sensor; for
the 9210/20-6 it is 0.45 times the
voltage across the sensor. TP 25
is the set point voltage and is of
opposite sign from TP 24.
These
two voltages algebraically sum to
the error signal.
5.7
TROUBLESHOOTING
Information on troubleshooting the
Model DRC-93C controller is contained in this Section.
5.7.1
Sensor Current
If the sensor current is not within
specifications (Section 5.5.3) then
adjust the current trimpot on the
input card (Section VII)
.
COPYRIGHT 3/88 LSCI
Model DRC-93c
5.7.1 Monitor Voltage, Display
Voltage or Resistance
The display reading in volts or
resistance should match the monitor
reading and the voltage across the
sensor, except for the 9215, 9305,
9317C and 9318C input cards and the
-6 configuration. If the readings
do not match then the input card
should be calibrated. If the monitor reading is incorrect and can
not be adjusted then the following
IC's may need to be replaced.
“Old” Input cards
1. 8210, 8211 cards - replace U5
2. 8219, 8220 cards
replace U5.
-
If that does not solve the
problem then replace U4.
“New” Input Cards
1. 9210, 9220 cards
replace U5
2. For the 9318C, the monitor voltage should be approximately
±10mV. If it is not between 516mV then U16, U13 or U10 could
be bad. For the 9317C the monitor voltage should be approximately a factor of ten lower.
The same three IC's are
involved.
-
If the monitor voltage is incorrect, the input card may control at
an offset or not at all.
If the sensor voltage matches the
monitor voltage and the display
voltage is incorrect then the A/D
needs to be calibrated.
5.7.2 Units Display is correct but
temperature reading is incorrect
If the units display matches the
voltage or resistance value of the
sensor, but the temperature display
is incorrect then check the curve
selected. This can be accomplished
by holding down the CURVE# button
or by reading the selected curve
over the interface using the W1
command.
COPYRIGHT 3/88
section
v
If the correct curve is selected,
but the display in temperature is
still incorrect, then check the
data in the curve.
This can be
done over the IEEE by using the
test program and the XDN1N2
command.
5.7.3
The Heater Circuit
If the DRC-93C does not have output
power check to see that U13 on
Figure 93C-1C (the IM317HVK) is
tightly screwed into its heat sink.
It is on standoffs near the fan in
the left rear of the unit.
Configure the DRC-93C as in Section
5.5.6.2.
Verify that there is
heater current going to the load
resistor.
Next, measure the analog out signal
to be sure the PID circuits are
operating correctly.
The analog
out signal can be measured at TP28
(Gnd at TP1). If this is a positive value that varies from 0-7.3
volts as the gain setpoint, or
reset values are changed then the
circuit is probably operating correctly.
Now measure the voltage
across from TP19 to TP21.
The
voltage should vary from 0 to 1
volt as the analog out signal varies from 0 to 7.3 volts.
As the
gain or manual heater is increased
the analog signal will increase and
the voltage between TP19 and TP21
will in-crease.
If the voltage
stays at 0 Volts then U45 or U46 is
probably bad as long as the raw
V+(TP21 to TP6) is close to 28
volts for the 10-25 Ohm Heater
Range (37 and 53 volts for the 2535 and 35-50 Ohm Heater Ranges
respectively).
The V+ can be
checked by measuring approximately
28V from TP21 to TP1. The V+ value
is 50 Volts if a W50 watt option is
installed in a DRC-91C or if the
resistor setting is 50 ohms on the
DRC-93C.
If a W60 Watt option is
5-7
Section V
Model DRC-93c
installed the V+ voltage should be
approximately 44 volts.
DO NOT CHANGE the Heater
Range switch when the u n i t is on.
Changing this s w i t c h w i t h the unit
on WILL DAMAGE the unit.
NOTE:
If the Voltage from TP19 to TP21 is
correct, and there is no heater
power on any range than U47 or U48
are probably bad and both should be
replaced.
Before it is decided
that U47 and U48 are bad be sure
the relays K4-K8 are working. If
they can be heard clicking as they
are turned off and on, then they
are probably operating properly.
They are turned off and on by selecting different heater ranges.
5-8
COPYRIGHT 3/88 LSCI
Table 5-1: Input Card Characteristics
Note 1: The lower temperature limit is dependent upon resistance-temperature characteristic of sensor used.
Note 2: 0.1µA to 1.0mA. Sensor voltage pinned at 1mV (9317C) or 10mV (9318C).
Note 3: To read correctly in temperature these input cards must be used with calibrated sensors
and the 8001 precision option.
Note 4: 9317C and 9318C will read to 1 ohm full scale w i t h reduced accuracy.
5-8
COPYRIGHT 12/87 LSCI
R E P L A C E A B L E P A R T S LIST
ITEM
NO
c1
LSCI P a r t
Number
QtY
-
D R C - 9 3 C M A I N BOARD
Description
MFR
MFR P A R T NO
101-275
101-225
1
10
CAP,ELECT19500MF,15V
CAP,ELECT,470MF,35V
MEP
PAN
C23
C40,42
46,50
CR2-6,
101-238
101-034
1
4
CAP,ELECT,2100MF,75V
CAP,PP,1MF,100V
MEP
FDYNE
3186BA212UO75AMA1
MPP2X-1.0-100-10
102-008
6
BRIDGE RECTIFIER
GI
w02m
C R 7 - 10
102-003
8
DIODE RECTIFIER
MOT
MR501
CR12,13
CR19
CR20
J4
102-001
102-058
102-053
1 0 6 - 3 10
106-412
106-146
106-139
106-143
1 0 6 - 129
106- 321
2
1
1
1
1
2
2
1
4
2
MOT
MOT
MOT
AML
TBAN
MOL
MOL
MOL
SAMT
1N 4 0 0 6
1N 4 7 4 9 A
102-072
113-063
1
1
2
DIODE RECTIFIER
DIODE, ZENER 2 4 V
DIODE, ZENER 5.1V
CONNECTOR ( I E E E )
CONNECTOR (REMOTE I D )
CONNECTOR ( T X 1 TO M B )
CONNECTOR ( T X 2 TO M B )
CONNECTOR ( B P TO M B )
CONNECTOR POSTS
RELAY,DPST,DRY
REED
DRY REED RELAY, 20 W
DRY REED RELAY, 50 W
T R A N S I S T O R , PNP
RES,PREC,100K,.01%
MATCHED P A I R
RES,MTF,30.1
,1/4W,1%
RES,MTF,9.84
,1/4W,1%
, 1 W,1%
RES,MTF,2.92
, 3 W,1%
RES,MTF,3.5
, 3 W,1%
RES,MTF,1.25
R E S , WWD, 5 8 7
5 W,1%
POWER S W I T C H ( 2 P O L E )
D I P SWITCH 8 POS
CONNECTOR ( 2 5 / 5 0 )
CONNECTOR (18/36)
REGULATOR, +5V
REGULATOR, - 5 V
REGULATOR, + 1 5 V
C2,6,10
7,13,16
18,20,
26,28
11
26-29
55
J A 1 ,2
JC1,2
JF
JG, J H
K1,2
K3 K 7
K8
Q1
R35,36
-
105-302
105-304
5
COTO
EAC
EAC
MOT
LSCI
.
3188BA952U015AMA1
ECEAIVV471S
1N751A
57-92245-12
609- 1 6 0 2 M
2630-09-74-1091
2630-09-74-1041
2630-09-74-1061
TSW-120-04-06
CR-3402-05-91
B1A5AH
P 1A 5 A
2N3906
103-209
103-495
103-540
103 586
103-583
103 6 7 5
105-014
105-408
106-229
106-227
102-011
102-021
102-014
1
1
1
1
1
1
1
3
4
3
2
1
102-024
102-012
102-022
102-036
1 0 4 - 71 2
1 0 4 - 71 0
104-711
104-529
104-310
104-419
104 061
104-408
104-076
104-088
3
1
1
1
1
1
1
2
1
1
1
3
1
3
REGULATOR, - 1 5 V
REGULATOR, +8V
R E G U L A T O R , -8V
REGULATOR, ADJ, 1 . 2 - 5 7 V
IC, IEEE CHIP
I C , I E E E SUPPORT C H I P
I C , I E E E SUPPORT C H I P
I C , PORT EXPANDER
IC, 8 B I T MULTIPLEXER
I C , 16 B I T D / A CONVERTER
IC, DISPLAY DRIVER
I C , 10 B I T D / A CONVERTER
I C , DUAL SPDT ANL SWITCH
I C , QUAD OP AMP
NAT
T I
T I
T I
1NT
NAT
BB
NAT
IS L
HAR
TSC
79151CT
7808CT
7908CT
LM317HVK-STEEL
TMS9914ANL
SN75160AN
SN75161AN
82C55A-5
81LS95
DAC703BH-5
MM5480N
AD7533JN
H15043- 5
TSC914A
U 31
104-162
104-355
1
6
IC,
IC,
NAT
GI
MM5451N
740L6000
U38
104-356
1
1
2
2
1
1
1
1
1
1
I C , OPTOCOUPLER
I C , 8 B I T A I D CONVERTER
I C , H E X I N V E R T E R , O.C.
IC,LIN,F/V
OR V / F
I C , OP AMP, J F E T I N P U T
POWER M O S F E T , 9 0 V N - C H
I C , OP AMP, D U A L M C 1 7 4 1
P W E R MOSFET, 1 0 0 V P - C H
C A B L E (MB TO U 1 )
SOCKET, T O - 3
GI
NAT
7 4 0 L 6 0 10
ADC0831CCN
7406
LM331N
LF356N
VN0109N5
1458PI
I RF9130
R63
R64
R65
R66
R67
R 76
s1
s3,5,7
SL0-3
SL4-6
U2,10
u3
u4,7
11,12
14
U5,8,15
U6
u9
U13
U16
U17
U18
U19,20
u2 1
u22
U23
U24-27
U28
U 2 9 ,3 0
32
u33-37
43
u39
U40,41
U42,44
u45
U46
u 47
U48
W1
XU13
-
-
-
104-453
104-210
1 0 4 - 01 0
104-022
102- 104
1 0 4 068
102- 095
-
106-571
5
DISPLAY DRIVER
OPTOCOUPLER
IT T
GY H
BRDY
BRDY
MOT
NAT
NAT
SPTX
MOT
IR
LSCI
AUG
F-01-2UEE/NE15-1B
76SB08
PWBH25DBF1F
PWBH18DBS1B
MC7805ACT
7905CT
7815CT
M8080-1G40
REPLACEABLE PARTS L I S T
ITEM
LSCI P a r t
Number
-
DRC-93C
QtY
Description
113-131
1
106-010
1 0 6 - 0 12
106-414
1 0 6 - 4 15
1 0 7 - 0 17
115-006
110-014
2
1
2
2
1
1
1
CONNECTOR K I T
consisting o f
5 P I N PLUG
MATE TO J 3 :
7 P I N PLUG
M A T E T O J5:
16 P I N I D C S O C K E T
16 P I N S T R A I N R E L I E F
RMA I N S E R T S
POWER C O R D
FUSE: 1 . 0 A SB ( 1 1 5 VAC)
0 . 5 A SB ( 2 3 0 V A C )
H6
1 0 5 -671
105-676
105-677
10
4
19
KEY TOP
KEY TOP
KEY TOP
F1
106-028
1
JF
106- 140
110-150
106-011
1 0 6 - 0 13
106-002
106-001
3
1 0 3 765
102-095
106-571
1
1
1
AC L I N E CORD P L U G / F U S E
HOLDER/LINE VLTG SLCTR
C N N C T R ( J 3 ON R B T O M B )
CONNECTOR T E R M I N A L S
CONNECTOR 5 P I N SOCKET
CONNECTOR 7 P I N SOCKET
GRAY
HEATER H I OUT
BLACK
H E A T E R L O OUT
BLACK
H E A T E R GND
POT,20 O H M , 1 0 % , L I N TAPER
POWER M O S F E T , 1 0 0 V P - C H
SOCKET,TO-3
TX 1
TX2
109-019
109- 021
1
1
B1
107-180
1
NO
MP3
H7
H8
J1/2
J3
J6
J7
J8
R68
U48
XU48
-
18
2
1
1
2
MFR
MFR P A R T
NO
LSCI
113-131
AML
AML
TBA
TBA
LSCI
126- 127
126-195
609- 1630
BUS
BUS
MDL-1
MDL 1 / 2
LSCI
LSCI
LSCI
105-671
1 0 5 -676
105-677
SFR
FN372-6/22
MOL
MOL
AM L
AML
EFJ
EFJ
2139-09-50-3061
2878-08-50-0116
1 2 6 - 2 18
1 2 6 - 198
111-0113-001
111-0103-001
CLAR
I R
AUG
LSCl-765
IRF9130
M8080-1G40
I N P U T TRANSFORMER
OUTPUT TRANSFORMER
LSCI
LSCI
C696-114
C696-115
FAN ASSEMBLY
LSCI
107-180
-
-
-
-
BLUE
L I G H T GREY
M E D I U M GREY
-
-
-
609-1631SP
107-017
REPLACEABLE PARTS L I S T
ITEM
NO
LSCI P a r t
Number
QtY
-
DRC-93C D I S P L A Y AND D I S P L A Y D R I V E R BOARDS
D e s c r i p t i o n
ON D B )
ON D B )
J1,2,4
J3
S1-33
106-151
106- 150
105-651
3
1
33
CONNECTOR(HEADER
CONNECTOR(HEADER
SWITCH
c1
C14
C17
CRI-3
J1-2,4
J3
01-10
U2,16
u3,11
U8
u12
U15,24
U17
U18
U19
u20
U23
101-132
101-137
101-144
102-062
106-153
106-152
102-072
104- 5 2 6
1 0 4 - 277
104-522
104-270
104-120
104-654
104-661
104- 5 2 8
104-511
104-653
1
1
I
3
3
1
10
2
2
1
1
2
1
1
1
1
1
CAP,TANT,1.5MF,10V
CAP,TANT,10MF,35V
CAP,TANT,33MF,25V
DIODE,SIL,SWITCHING
C O N N E C T O R ( S 0 C K E T ON D D B )
C O N N E C T O R ( S 0 C K E T ON D D B )
TRANSISTOR, SIGNAL PNP
I C , KEYBOARD INTERFACE
I C , 4 - 1 6 L I N E DECODER
I C , 1/0 EXPANDER
I C , 4 - 1 0 L I N E DECODER
I C , 3 - 8 L I N E DECODER
I C , 2 K NOVRAM W/CLOCK
IC, EPROM
IC, 8 B I T LATCH
I C , MICROPROCESSOR
I C , NOVRAM
MFR
M F R P A R T NO
ALP
ALP
ALPS
TDB24SG
TDBIOSG
K E F 10 9 0 1
SPRG
SPRG
SPRC
150D155X9010A2
119D106X0035DB1
196D336X9025PE-14
1N459A
1 1 0 3 18 3
1 0 3 18 3 - 4
2N3906
P8279-5
74HC154
P8243
74145
7 4 H C 138
MK48T08B-25
27C256
82C82
P 8 0 C 3 1B H
DS1225Y
AMP
AMP
IN T
INT
MOS
MOS
I NT
I NT
DAL
-
Figure 93C-1 a. Component Layout
- DRC-93C Main Board
Figure 93C- 1a. Component Layout
- DRC-93C Main Board
Figure 93C-1 b. Schematic
-
DRC-QSCMaln Board +1 (Input Power Supply)
Figure 93C-ld.
Schematic - DRC-93C Main Board +3 (Digital Section)
Fig
3
. Schemat
R
tions)
Figure 93C-1f. Schamatic
-D
d Summation)
Figure 93C-1g. Schematic
- DRC-93c Main Board +6 (PID
Control)
Figure 93C-1h Schematic
-
DRC-93C Main
+7 (Output Stage)
Figure 93C-1 i. Schematic - DRC-93C Main Board +8 (Rear Panel Interconnector
Figure 93C-2a. Component Layout = DRC-93C Display Board
Figure 93C-2b.
Component Layout
-
DRC-93C Display Driver Board
Figure 93C-2c. Schematic
- DRC-93C
Display Board +1 (Setpoint Section)
Figure 93C-2d. Schematic - DRC-
C Display Board +2 (Inp
Display Section)
Figure 93C-2e. Schematic
- DRC-93C
Display
d +1 (Digital Section)
Figure 93C-2f.
Schematic
- DRC-93C Display Driver Board +2 (Bar Graph Drive Section
Figure 93C-2g. Schematic
- DRC-93C
Display Driver Board +3 (Display Matrix)
ITEM
NO
C1
C2
C5
C13
U1
U2
U3
U4
U5
U6
U7
U8
Y1
LSCI P a r t
Number
37
59
18
101 144
-
104-511
Q ty
1
1
Description
MFR
MFR
P A R T NO
. Microprocessor Card
Section VI
Model DRC-93C
S E C T I O N
P R O G R A M M I N G
I N S T R U C T I O N S
6.1 INTRODUCTION
This section contains information
and instructions concerning the
Internal Program feature of the
Model
DRC-93C Temperature
Controller. The feature permits
simple ramp and Dwell (or Soak) as
well as elaborate sequences
including ramping the setpoint up
and down and ramping of the gain,
rate and reset.
The DRC-93C is capable of
automatically executing internally
stored programs. The programs are
entered into the instrument from
the front panel. The programs are
permanently stored in a nonvolatile
memory permitting their execution
even though the instrument has been
turned off and on, unplugged and
moved. The instrument comes from
the factory with a repertoire of
example stored programs which rampand-soak, etc.
These programs
allow the user to quickly learn the
contents of this chapter and many
can be used directly with minor
modification of the setpoint and
control parameters.
6.2
V I
PROGRAM STEPS AND SIZE
three to four Programs Steps in
length, this provides storage for
many programs.
The Programmer Specifications are
summarized in Table 6-1.
Table 6-1 programmer Summary
Number of Stored Programs - limited
by a total of 99 steps: for
example, 49 Ramp and Dwells
- Up to 99
Commands - 8 different
Steps per Program
Programming
commands
Ramp Formats - Total of 3: ramp
setpoint up, ramp Setpoint Down,
and ramp setpoint, gain, rate and
reset to a final value
Ramp Time - 0 to 30 days: specified
in days, hours, minutes and seconds
Repeat Cycles - 99 per step: can be
multiplied by using additional
steps
6.3
PROGRAM
STEP FORMAT
The Program Steps of the internal
programming feature are very
powerful.
A single Program Step
contains information to enable the
instrument to ramp the setpoint to
a given value with control
parameters selected for that
ramping function. A single Program
Step is all that is necessary to
provide a soak with all parameters
desired.
Each Program Step contains the Step
#, Command and JUMP VECTOR, REPEAT
COUNT or RAMP COUNT as well as a
full description as indicated by
the front panel. These are listed
below.
simple ramp and soak requires
only two Program Steps---one to
ramp and one to soak.
5.
6.
7.
A
There are provisions for 99 Program
Steps. Since typical programs are
COPYRIGHT 12/87 LSCI
1.
2.
3.
4.
8.
9.
Sample and Control Sensors
Sample and Control Units
S a m p l e and
Control
Resolutions
Setpoint
Gain, Rate, and Reset
Manual Heater Power
Heater Range
Program Timer
Filtering on/off
6- 1
Section VI
0
Null
1 Dwell
2
Dwell
Model DRC-93C
TABLE 6-2
PROGRAMMING COMMANDS
#.0.REPEAT COUNT.
D o e s nothing b u t e n t e r a REPEAT
Step
count
i n t o the REPEAT COUNTER associated w i t h Command 2 and
move t o the next P r
am Step #. N o f r o n t panel parameters
can be changed
Null Command. This command is used
i n conjunction w i t h Command 2 (Dwell) t o establish a do
loop.
The REPEAT COUNT number estab ishes the number of
t i m e s a given set of operations w i l l be repeated.
Ste
#.1.JUMP VECTOR.
D w e l l (Soak) f o r the time given
(set
w i t h Time ke ) w i t h the f r o n t panel parameters set i n
the program s t e p ormat. A f t e r this d w e l l t i m e jump t o the
Program Step # specified by the JUMP VECTOR.
Step #.2.JUMP VECTOR
Dwell (Soak with Conditional Jump.
Same as Programmin Command 1 exce
t h a t when the Dwell is
completed, the
COUNTER
b
Command 0) is
decremented.
I f the value of the
COUNTER ,is nonzero o e r a t i o n continues a t the P r
a m Step s p e c i f i e d by
the
VECTOR. I f the REPEAT
is zero then opera t i o n continues a t the next Program Step #.
Step #.3.RAMP COUNT.
Ramp the setpoint Up. The s e t p o i n t
is incremented b the value given i n the s e t p o i n t d i s p l a
of t h a t P r ram Step (set w i t h Setpoint ke ).
The s e t p o i n t
is incremen ed t h e number of tunes s
by
RAMP
COUNT .given i n the. l a s t two d i g i t s o f t h e Upper Display.
The t i m e f o r each increment is s ecified by he timer i n
the Program Step (set with TIME key)
A f t e r rampin the
s p e c i f i e d number of times
iven by the RAMP
operation continues a t the
Program Step #.
All other
parameters change t o the displayed values o n e n t e r i n g this
command during program operation a t the beginning of the
ramp. This command is normall used for rapid warmup where
ramp times exceed 0. 1K/second
step #.4.RAMP COUNT.
Ramp the Setpoint Down
Same a s
Pr ram Command 3 exce t t h a t t h e set o i n t is ramped down,
is, the s e t p o i n t is decremen ed by the quantity
specified i n the s e t p o i n t display.
A f t e r ram i n
the
specified number of tunes given by the
operation, continues a t t h e next p r o g r a m Step #.
This
command is normally used for rapid cooldown where ramp
t i m e s exceed 0.1K/second (6K/minute).
Step #.5.JUMP VECTOR.
Setpoint, Gain R a t e and R e s e t
Up or Down. The s e t p o i n t
Rate, and
are ramped
i n this Command.
The, s e t p o i n t is incremented or
decremented i n its least s i g n i f i c a n t b i t at a rate given i n
the tuner o f the Program S t e
The s e t p o i n t begins a t the
value given i n the previous
Step and increments o r
decrements t o the value s p e c i ied i n this Program Step.
the g a i n rate and reset are decremen ed o r inSimilar1
cremente
required t o ram from the value given i n the
reviously execu ed Pr ram S t e p t o the value, s p e c i f i e d i n
Program Step
ramping the specified amount,
operation continue; a t the Program Step # indicated by the
f
REPEAT
JUMP
3
Ramp Up
.
cified
me
COUNT
4
RampDown
5Ramp
.
that
Count
gain
this
Reset
After
VECTOR.
8
Jump
9
Exit
6-2
#.8.JUMP VECTOR.
Jump to the
r
Step specified
e,JUMP VECTOR The previous parameters are used and
ose i n t h e Program Step are ignored.
step #.9.00.
Brit the Internal p
resuming normal
operation w i t h the f r o n t panel
given i n t h i s
command.
Ste
values
COPYRIGHT 12/87 LSCI
Model
6.4
Section vI:
DRc-93C
SUMMARY OF COMMANDS
The Program Commands are summarized
in Table 6-2. When the temperature
has been stabilized at the
Setpoint, the Dwell command is
essentially a Soak command.
6.5 INTERNAL PROGRAM ENTRY
A short description of the sequence
is as follows.
Additional
information is described in the
Sections listed in parenthesis.
1. Press the PROGram key.
The
PROGram indicator will flash on
and off (Section 6.5.1).
2. Press the INTernal key.
The
PROGram indicator will stop
flashing and turn on as will the
INTernal indicator (Section
6.5.1).
The Program Step is selected
using the POINT# key (Section
6.5.2).
4.
The command and JUMP VECTOR
(REPEAT COUNT) are entered
(Section 6.5.3).
5. The setpoint, gain, rate, reset,
heater range, manual heater
power, units, etc. are selected
(Section 6.5.4 and 6.5.5).
6. The
Timer value
(Section 6.5.6).
is selected
7. The SCAN key is pressed to store
the
Program
Starting the Program Edit
There must be a valid input
present when editing a program.
The DRC-93C incorporates fault
protection that w i l l automatically
force the HEATER RANGE to the OFF
state on an input overload (OL)
(section
condition.
To enter or modify a program in the
DRC-93C, the operation must be
started with the PROGram key. Next
press the INTernal key and it is
now possible to create or edit a
program. The Program Edit Mode is
depicted by having both the PROGram
and INTernal annunciator lights
lit.
6.5.2
Program
Step Selection
Upon entering the Program Edit
Mode, the display will always enter
at Program Step 01.
The Temperature and Setpoint Blocks
will show the contents of the first
Program Step (#01) as (for example)
01.2.02
00
00
20
00
-
The upper display shows the Program
Step # (01), the Program command
(2) and the JUMP VECTOR (02) which
tells the program which Program
Step # will next be executed.
8. Stages
The Setpoint Display contains the
Days and Hours and the Lower
Display the Minutes and Seconds of
Program Step #01.
9. After all steps of the program
If another Program Step is desired,
the user presses the POINT# key,
the point # desired followed by the
6.5.7).
Step
6.5.1
Mode
NOTE:
This section discusses the
procedure for entering an internal
program.
3.
are entered, the PROGram key is
pressed to exit the programing
mode.
The PROGram indicator
turns off and normal operation
will resume (Section 6.5.8).
3.
through 7. are
repeated to enter more Program
Steps.
COPYRIGHT 12/87 LSCI
6-3
Model DRc-93C
Section VI
The new Program Step #
and information is then displayed.
ENTER key.
A t any tIME that the POINT# key is
Commands 3 and 4 the e n t r y i n t o the
Setpoint is an incremental value
whereas for a l l o t h e r s it is an
a c t u a l Setpoint.
be used t o select the next higher
6.5.5
appropriate, the
key o r
key can
or
lower
Program S t e p
#
respectively. The
key and
key
do not operate i n any o t h e r case
f o r any o t h e r purpose except t o
increment or decrement the Program
Step # a t a t i m e when it could be
entered using the POINT# key.
A f t e r the desired Program Step #
has been selected and displayed,
the u s e r can e n t e r o r modify (as
required) t h e Command, the JUMP
VECTOR,
REPEAT COUNT or RAMP
COUNT) , Sensor#, Units, Setpoint,
Gain, Rate, R e s e t , Manual Heater
Power, Heater Range, and Timer.
6.5.3 Entering the Program COmmand
and JUMP V, REPEAT COUNT or
RAMP count
When a Step# is selected, the
command p o s i t i o n w i l l flash. I f a
number is entered, then the command
w i l l change t o t h a t number.
When
the desired number is displayed
press the ENTER key. Then the JUMP
VECTOR, REPEAT COUNT o r RAMP COUNT
position w i l l flash.
I f it is
c o r r e c t p r e s s the ENTER key.
If
not, then e n t e r the new value w i t h
the keypad followed by the ENTER
key.
A t this point the s e t p o i n t ,
etc. may be changed.
gain,
6.5.4 Entering the Setpoint, Gain,
Rate and Reset
The Setpoint, Gain, R a t e , R e s e t ,
and Manual Heater Power f o r the
S t e p are changed as
i n Chapter 3.
For
example, t o change the Setpoint,
press t h e SETPOINT key followed by
the keypad d i g i t s ,
key or
key
a s desired. Pressing the ENTER key
s t o r e s the r e s u l t .
Note that f o r
Program
described
6-4
Entering Other Parameters
I n addition, the sensor u n i t s ,
resolution,
f i l t e r i n g of either
display, Manual H e a t e r P o w e r and
H e a t e r Range can be changed f o r any
POINT #.
6.5.6
Entering the Timer Value
Time
(Timer)
displayed is
changed u s i n g t h e TIME key.
Pressing the TIME key causes the
Days e n t r y t o flash. The keypad is
used t o e n t e r the Days. A f t e r the
Days desired is shown, t h e u s e r
presses the ENTER key.
The Days
w i l l s t o p flashing and the Hours
w i l l f l a s h . The Hours, Minutes and
Seconds are entered i n t h e same
way. The t i m e value should be nonzero f o r commands 1, 2 , 3, 4 and 5.
The
6.5.7
Entering
into Memory
the Program Step
Once a l l parameters of a s t e p a r e
as desired, pressing the SCAN
key w i l l e n t e r t h a t program
s t e p i n t o memory. I f the SCAN key
is n o t p r e s s e d , the program s t e p is
not s t o r e d and subsequent request
f o r the program s t e p w i l l produce
the old configuration.
6.5.8
Ending o r
programming Mode
Aborting
the
If it is desired t o end or abort
the operation a t any time (except
when the s e t p o i n t , gain, rate,
reset, manual h e a t e r power, o r time
is i n the progress of being entered), p r e s s t h e PROG key. The PROG
i n d i c a t o r w i l l t u r n o f f and
operation w i l l r e t u r n t o normal.
COPYRIGHT 12/87 LSCI
section VI
Model DRC-93c
6.6 RUNNING THE PROGRAM
To begin execution of the internal
program,
the user does the
following.
1. Press the INTernal key.
The
INTernal indicator will begin to
blink on and off.
2. Select the Program Step using
the POINT# key followed by the
ENTER key.
another Program Step is
desired, repeat step 2. The
key or
key can be used to
examine the next higher or lower
Program Step # respectively.
3. If
4. If it is desired to return to
normal operation thus aborting
the programming setup, press the
INTernal key.
The INTernal
indicator will turn off and
normal operation will resume.
the SCAN key to begin
execution of the program
beginning at the Program Step
The
selected in part 2.
INTernal indicator will turn on
and stay on showing that the
instrument is in the programming
mode.
6.7 CLEARING A l l INTERNAL PROGRAM
MEMORY
internal program memory can be
cleared of program material from
the front panel. The procedure is
as follows.
ALL
1. Press the PROGRAM key.
2. Press and hold the CLEAR key f o r
approximately 15 seconds until
the PROG indicator goes o f f .
ALL program
steps will be
cleared
and
front panel
operation restored.
6.8 EXAMPLES
6.8.1
Example #1 - Ramp and Soak
In Figure 6-1 is shown a graph of a
simple ramp from 40K to 100K in a
period of 30 minutes and a soak
(dwell) of 1 hour.
Step #02
dwell=1 hour
5. Press
6. The
only keys active while a
program is being executed are
the CLEAR key and the TIME key.
Pressing the CLEAR key causes
execution of the program to
cease and operation to be
returned to normal.
Pressing
the TIME key causes the elapsed
time in a particular cycle to be
displayed.
7. To
exit from the programming
mode, press the CLEAR key. The
INT indicator will turn o f f . It
is also possible to exit the
program by using command 9.
COPYRIGHT 12/87 LSCI
100K
Step #01
Ramp for 30
minutes
4 OK
Figure 6.1 Simple Ramp and Soak
It is assumed that the system has
stabilized at 40K prior to
execution of the program.
Step #01 and #02 will be used f o r
the program.
Step #01 will ramp
and Step #02 will dwell.
It is
assumed that the system can follow
the setpoint in the time provided.
6-5
Section VI
Model DRC-93C
Step #01 will look as follows.
setpoint
-
setpoint
Gain
Rate
Reset
01.3.60
00
00
-
- 30
00
1.0
20
0
10
The command selected is 3 for
Setpoint ramp up. The RAMP COUNT
is 60. The setpoint will ramp up
by the amount specified in the Step
#01 setpoint display every 30
seconds for 60 times.
The setpoint of step #01 will be
set to 1K to indicate 1K step up
every 30 seconds for a total of 60
steps or 60K in 30 minutes (1800
seconds).
The gain, rate, and reset will
remain constant during the ramp as
specified in Step #01.
The soak is covered by Step #02 as
follows.
Days
Minutes
- Hours
- seconds
setpoint
Gain
Rate
Reset
02.1.03
00 - 01
00
- 00
6.8.2
Example #2
- Ramp and Soak
The ramp and soak of Figure 6.1
will be accomplished in this
example with command 5 ramping. It
will be necessary to fix the
setpoint at 40K prior to the ramp.
Here it will be set to dwell for 10
minutes.
The entire process is
shown in Figure 6.2. Steps #4, #5,
and #6 are used.
100K
Step #05
Ramp for 30
minutes
4 OK
Step #4,Dwell 10 minutes
Example #2
Figure 6.2
0
5
STEP #03
-
.
03 9-00
00
00
- 00
- 00
Step
#04
will look as follows.
Step #04
-
04.1.05
00
00
setpoint
40.0
Step#.cammand.JUMPVECTOR
Days
HOURS
minutes
- seconds
Gain
Rate
Reset
6-6
OFF
Note that the Setpoint, gain, rate,
reset, etc. are part of command 9
and will be installed as the
parameters when normal operation
resumes. Setting the setpoint to 0
will remove power to the system as
will setting the Gain to 0 or
setting the Heater Power to 0.
100. 0
10
If it is desired to shut down the
controller after the one hour soak,
step 3 will be as follows:
Step#.command.
Days
Hours
Minutes-seconds
0
H e a t e r Power
STEP #02
Step#.cammand.JUMp VECTOR
0
0
Rate
Reset
STEP #01
Step#.Command.RAMP COUNT
Days
Hour
Minutes-seconds
0.0
Gain
10
- 00
10
0
10
COPYRIGHT 12/87 LSCI
Model Dwc-93C
Step #05 will look as follows.
Days
VECTOR 05.5.06
- HOU~S
seconds
setpoint
Gain
Rate
-
00
00
00-03
100.0
10
0
5
Reset
The command selected is 5 for
Setpoint ramp. The JUMP VECTOR is
06 so that operation after the ramp
goes to Step #06. The setpoint of
step #05 will be set to lOOK to
indicate where the ramping will
end. Note that even if the t h e
were selected incorrectly, the
ramping would still end at 100K.
It is necessary to select the timer
increment per tenth to arrive at
the lOOK in the 30 minutes.
From 40K to lOOK is 600 tenths. It
will require 600 increments of 3
seconds each to end up at 100K in
30 minutes (1800 seconds)
Thus
the setpoint will ramp up by 0.1K
every 3 seconds up to lOOK and will
reach lOOK in 30 minutes.
.
The reset will ramp from the value
given in Step #04 to those
specified in Step #05.
The soak is covered by Step #06 as
follows.
STEP 906
-
06.1.03
00
01
00
00
setpoint
100. 0
10
0
5
Step#.Comuand.JUMP VECTOR
Days H m
seconds
Gain
Rate
Reset
-
After the soak, the next Program
Step will be Step #03 which has a
Command 9 and is explained at the
end of Example #l.
COPYRIGHT 12/87 ISCI
Example
#3
-
Repeated
setpoint Ramp Ilp, soak, and Ramp
DOwn with G a i n
STEP #05
Step#.-.JTJMP
6.8.3
section VI
Ramping
The ramp up, soak, and ramp down
shown in Figure 6.3 will be
repeated indefinitely in this
example.
The first part of the
example is identical to that given
in Example #2 except that the gain
will be ramped up from 10 to 20 and
held at 20 for the lOOK soak (See
Figure 6.4).
Steps #07, #08, and
#09 and #10 will be dedicated to
this example.
Step #09
1 hr
lOOK
Step #08
30 minutes
4 OK
Step #10
20 minutes
Step #7,Dwell 10 minutes
Figure 6.3
Example #3-Setpoint
Step #09
1 hr
20
10
Figure
6.4
Example #3-Gain
Step #07 and #08 are identical to
Steps #04 and #05 of Example #2 and
are repeated here.
6-7
section v1:
Model uRc-93C
STEP #07
Step#.Command.JUMP
-
VFATOR 07.1.08
Days
HOU~S
Minutes-seconds
setpoint
00
- 00
10-00
40.0
Gain
10
0
10
Rate
Reset
STEP #OS
Step#.Cammand.JUMP VFATOR 08.5.09
Days
HOU~S
00
00
-
-
Minutes-secOnds
00-03
setpoint
100. 0
20
0
5
Gain
Rate
Reset
The soak is covered by Step #09 is
the same as Step #06 of Example #2
except that the JUMP VECTOR is t o
Step #lo.
s!rm
#OS
Step#.casnmand.JUMP VFATOR
Days
Minutes
- hour^
- seconds
setpoint
09.1.10
00
01
00
- 00
100. 0
20
0
5
Gain
Rate
Reset
A f t e r the soak, t h e next Program
Step w i l l be Step #10 which is t o
ramp down.
STEP
#lo
setpoint
Gain
Rate
Reset
-
40.0
10
0
10
The JUMP VECTOR of Step #10 is t o
Step #07. I n this way the e n t i r e
sequence is repeated u n t i l the
6-8
The command f o r Step #10 is 5 f o r
Setpoint ramping. The s e t p o i n t of
s t e p #05 w i l l be set t o 4 0 K t o
i n d i c a t e where the ramping w i l l
end. Note that even i f the time
w e r e selected i n c o r r e c t l y , the
ramping would still end a t 40K. I t
is necessary t o select the t i m e r
increment p e r t e n t h t o a r r i v e a t
the 40K i n the 1 0 minutes.
From 40K t o lOOK is 600 t e n t h s . I t
w i l l require 600 increments of 1
seconds each t o end up a t 40K i n 1 0
minutes (600 seconds).
The gain w i l l ramp up during Step
#08 and ramp down during Step #lo.
-
6.8-4
Example #4
R e p e a t of
Example 3 with a Limit of 10 Cycles
STEP #11
Step#.cosnmand.RepEAT
COUNT 11.0-10
STEP #12
Step#.cammand,JcJMp VECIOR 12.2.14
Days
Minutes
- hour^
- seconds
Setpoint
00
10
-
00
- 00
40.0
10
Gain
Rate
Reset
0
10
STEP #13
Step#.Command.JUMP VECTOR 10.5.07
Days
Haur~
00
00
seconds 0 0 - 0 1
-
operator presses the CLEAR key t o
terminate the program mode.
Step#.Command.JUMP
VECIDR 13.8.17
STEP #14
Step#.Camwmd.JUMP VEePoR 14.5.15
Days
HOU~S
00
00
-
Mh~tes-seconds
setpoint
Gain
Rate
Reset
-
00-03
100.0
20
0
5
COPYRIGHT 12/87 LSCI
Model DRC-93C
Section VI
STEP #15
Minutes-seconds
15.1.16
00
01
00
00
setpoint
100 0
Step#.Cosmarand.JIlMP VECIOR
Days HOWS
-
Gain
Rate
Reset
-
20
.
0
5
STEP 1/16
Step#.cbamnand.J[lMp VECroR 16.5.12
Days
HOU~S
00
00
-
-
M i n u t e s - ~ n d s 00-01
setpoint
Gain
Rate
Reset
40.0
10
0
10
STEP #17
Step#.Cammand.OO
setpoint
Gain
Rate
Reset
COPYRIGHT 12/87 I S C I
17. 9.00
40.0
10
0
10
6-9
SECTION VI1
ACCESSORIES.
INPUT CARDS A N D OPTIONS
T A B L E OF C O N T E N T S
MODEL OR
PART NUMBER
DESCRIPTION
ACCESSORIES
RM-3F
8072
8271-04
8271-21
8271-22
HTR- 50
HTR-25
PAGE
.......
. . ..
......
..
.
Rack Mounting Kit
IEEE-488 Interface Cable
Scanner Sensor Cable for 8229
Sensor/Heater Cable
Sensor/Heater/Output Cable
50 ohm Cartridge Heater. 50 W
25 ohm Cartridge Heater. 25 W
.
..
.
.
.
.
..
.
.
.
.
..
.
.
.
...
.. .. ..
...
...
...
.......
INPUT CARDS
"Old" Input Card Dip Switch Definitions
(8210. 8211. 8219-P2. 8219.P3.
8219-R1)
9210
9215
9220
9305
9317C
9318C
8225
8229
9126
7-2
7-2
7-2
7-2
7-3
7-3
7-3
. . . .. .. .. .. .. .. .. .. .. 9210-1
9215-1
. . . . . . . 9220-1
. . . . . . . . . . 9305-1
. . . . 9317C-1
. 9318C-1
Diode Input Card
Capacitance Input Card
User configurable Input Card
Thermocouple Input Card
Ultra-low (0.3K) Resistance Card
Germanium/Carbon Glass Resistance Card
OPTIONS
8223
.
7-2
RS-232C Interface Option
Analog Output Option
Scanner Conversion Option
High Resolution Set Point
........
..........
........
........
8223-1
8225-1
8229-1
9126-1
Section VII
Model DRC-93c
7.1 INTRODUCTION
This section contains information
concerning the Accessories, Input
Cards and Options for use with the
DRC-93C Temperature Controller.
Each Accessory, Input C a r d and
Option is listed by part number in
the Table on page 7-1.
FU-3F Rack Mounting Kit
The DRC-93C can be rack mounted in
a standard 19 inch instrument rack
by using the RM-3F Rack Mounting
Kit.
The RM-3F mounts one
controller in a height of 3.5
inches.
Use
the following
procedure to install the RM-3F Kit.
1. Remove the two blue rack mount
access covers, if present, from
the front-side corners of the
unit to be rack mounted. This
is easily done by sliding the
cover up as far as possible and
using a blade screwdriver on
the bottom edge to remove it
from its position.
2.
If the -H (handles) option was
added, mount the handles onto
the rack ears.
3.
Attach the rack ears on
opposite sides of the unit.
7.2.2
7.2.2.1
Cable
Cables
8072
IEEE-488
- The 8072 IEEE-488 Interface
Interface
cable is one meter long and is
equipped with double-ended
connectors so it may be
interconnected in serial or star
patterns common in IEEE-488
instrument configurations.
7-2
- The
for the four additional input
sensors provided by the 8229
Option. The cable's mechanical and
electrical specifications are
included with the cable.
7.2.2.3
Cable
7.2 ACCESSORIES
7.2.1
8271-04 Scanner Sensor
8271-04 Scanner Sensor
cable for the 8229 Scanner Card is
3 meters long and brings out leads
7.2.2.2
Cable
8271-21
sensor/Heater
-is The
8271-21 Sensor/Heater
a six pair individually
Cable
shielded cable with two five pin
miniature hexagonal plugs which
mate with the SENSOR A and SENSOR B
connectors on the back panel of the
DRC-93C Temperature Controller. In
addition to the sensor connectors,
it has a dual banana plug for
heater output and a single banana
plug for heater output shield.
The cable's mechanical and
electrical specifications are
included with the cable.
7.2.2.4
/Output
8271-22 Sensor/Heater
Cable - The 8271-22
Sensor/Heater/Output Cable consists
of two discrete cables. The first
is a six pair individually shielded
cable with two five pin miniature
hexagonal plugs which mate with the
SENSOR A and SENSOR B connectors on
the back panel of the DRC-93C
Temperature Controller.
In
addition to the sensor connectors,
it has a dual banana plug for
heater output and a single banana
plug for heater output shield. The
second cable is a three pair
overall shielded cable for the
Monitors Outputs.
The cable's mechanical
electrical specifications
included with the cable.
and
are
COPYRIGHT 12/87 LSCI
Model DRC-93c
7.2.3
Section VII
Cartridge Heaters
DRC-82C can be used i n the DRC93C.
The DRC-93C w i l l recognize
these cards i f the dip s w i t c h
s e t t i n g s are set correctly.
This
Dip S w i t c h is located i n the r e a r
r i g h t hand corner of the main board
below the AC input connector.
7.2.3.1
50 Ohm Cartridge HeaterThis cartridge heater is 1/4" i n
diameter by 1" i n length and is
rated a t 50 watts.
-
7.2.3.2
25 ohm Cartridge Heater
This cartridge heater is 3/8" i n
diameter by 1" i n length and is
WARNING
rated a t 25 watts.
To prevent shock hazard, t u r n
off the instrument and disconnect it from the AC l i n e power
before changing the Input C a r d
switch s e t t i n g s .
I n s t a l l a t i o n of Input cards
from a DRC-81C or DRC-82C
7.3
Input cards from t h e DRC-81C o r
“OLD" INPUT CARD DIP SWITCH DEFINITIONS
BIT 0
BIT 7
2
1
5
4
3
6
7
8
0 (OFF)
OPEN
1
2
3
4
o o o x
001X
010X
100X
101X
110X
1 1 1 x
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
x
x
x
x
x
x
B INPUT CARD
5
6
7
8
A INPUT CARD
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
x
x
x
x
x
x
8210
8211
8219-P2
8219-P3
8219-R1
EMPTY
NEWCARD
NEWCARD
NEWCARD
NEWCARD
NEWCARD
NEWCARD
NEWCARD
NEWCARD
NEWCARD
NEWCARD
NEWCARD
NEWCARD
8210
8211
8219-P2
8219-P3
8219-R1
EMPTY
o o o x
001X
010X
100X
101X
110X
111X
1 (ON)
NEW CARD (NON 8210,8211 OR 8219)
ALSO COMBINATIONS OF A AND B
X DON'T CARE
COPYRIGHT 12/87 LSCI
-
SWITCHES 4 AND 8 ARE RESERVED
7-3
ode Input Card
R E P L A C E A B L E P A R T S LIST
ITEM
NO
LSCI P a r t
Number
QtY
-
9 2 1 0 A N A L O G INPUT
Description
U FR
CARD
MFR
PART NO
C11,17
101- 0 3 4
4
CAP,PP,1.0MF,100V
FDYNE
MPP2x-1.0-100-10
C16
1 0 1- 0 2 5
1
CAP,PP,.33MF,100V
FDYNE
MPP-11.33MFD
P2
106-142
1
MOL
2420-09-75-1061
ai
102-072
1
TRANSISTOR,PNP,SIGNAL
s1
105 649
1
SWITCH,2 P O S 8 4 POLE
INTERLOCKING
EGC
2XMTA7.5(NONE)
4UGRP
u1
102-074
104-005
102-043
104-001
104-355
104-356
1 0 4 - 099
104-461
104 460
104-051
1
1
2
2
MOSFET,P CHANNEL
I C , O P AMP
VOLTAGE REFERENCE,6.95V
I C , OP A M P
I C , OPTOCOUPLER
I C , OPTOCOUPLER
IC, P - S SHIFT REGISTER
I C , A / D CONVERTER
I C , A / D REFERENCE
IC, TIMER
SIL
3N163
18,28
u2
U3,17
u4,s
u6,8,9
u7
u10-12
U13
U14
U18
-
-
3
1
3
1
1
1
CONNECTOR,
(IC TO B P )
6 POST L O C K I N G HEADER
2113906
NAT
PUI
GI
GI
I SL
I SL
I SL
Lm308
LM399H
0p07e
740 L 6 0 0 0
7 4 0 16 0 10
C D 4 0 2 1BCN
ICL7104-16CPL
ICL8068ACPD
ICU7555IPA
R E P L A C E A B L E PARTS LIST
ITEM
NO
C11,17
18.28
C16
P2
LSCl Part
Number
QtY
Description
MFR
MFR PART NO
4
CAP,PP,1.0MF,100V
FDYNE
UPP2x-1.0-100-10
106- 142
1
CONNECTOR, (IC TO BP)
6 POST LOCKING HEADER
MOL
2420-09-75-1061
S W I T C H , 2 POS,4 P O L E
INTERLOCKING
EGC
101-025
102-072
ut
102 074
104-005
102 - 043
104-001
104-355
104-356
104-099
104-461
104 460
104-051
u2
U3,17
u4,5
U6,8,9
u7
u10-12
U13
U14
U18
9 2 1 0 ANALOG IYPUT C A R D
101-034
Q1
s1
-
1 0 5 - 649
-
-
1
1
1
1
1
2
2
3
1
3
1
1
1
CAP8PP,.33MF,100V
TRANSISTOR,PNP,SIGNAL
MOSFET,P CHANNEL
IC, O P A M P
V O L T A G E REFERENCE,6.95V
IC, O P A M P
IC, OPTOCOUPLER
IC, O P T O C O U P F E R
IC, P - S S H I F T R E G I S T E R
IC, A / D C O N V E R T E R
IC, A/D R E F E R E N C E
IC, TIMER
FDYWE
SIL
NAT
PU I
GI
GI
I SL
I SL
I SL
UPP-11.33MFD
213906
2XMTA7.5(NONE)
4UGRP
3N 163
1m308
LM399H
0p07e
740L6000
74 O L 6 0 10
CD4021BCN
ICL7104-16CPL
I CL8068ACPD
ICM7555IPA
Model DRC-91C/93C
9210 Diode Input Card
9210 D I O D E INPUT C A R D O P T I O N
9210.1 INTRODUCTION
Table 9210-1.
9210 Diode Card
This section contains information
pertaining to the Model 9210 Diode
Input Card.
Included is a
description,
specifications,
installation, operation and
maintenance information.
Sensor (ordered separately):
DT-470 series, MI-500 series
and TG-120 series from LSCI as
well as any other diode sensor.
See Lake Shore Diode Sensor
brochures.
9210.2 DESCRIPTION
TemperatureRange: Dependent
on Diode Sensor. See Sensor
brochure.
The Model 9210 Diode Input Card is
designed to be installed in a
DRC-91C or DRC-93C to convert
either the Input A or Input B (or
both with two options) t o
accommodate diode sensors with a
voltage output of up to 3.0000
volts (9210-3 configuration), The
9210-3 is used with Lake Shore
DT-500-DRC
or DT-470 Series
Sensors.
Calibrated DT-500 or
DT-470 Series Sensors can be
accommodated with an 8000 Series
Precision Option.
The 9210-6 configuration will
accommodate diode sensors (TG-120
series) with voltages between 0 and
6.5535 volts. A calibrated sensor
and 8001 Precision Option is
required for the DRC-91C/93C to
read accurately in temperature.
9210-3 can be converted to 9210-6
configuration by switch on the 9210
Diode Input Option Card.
This
configuration will also read DT-470
and DT-500 series sensors but with
reduced resolution and accuracy.
See Table 9210-1,
9210.3 SPECIFICATIONS
Specifications for the Model 9210
Diode Input Card are given in Table
9210-1. The card can be configured
by the user as either a 3 volt
(9210-3) or a 6 volt (9210-6) card.
COPYRIGHT 12/87 LSCI
sensor Excitation: DC current
source. 10 microamperes
(±0.005%).AC current noise less
than 0.01% of DC current.Compliance voltage
7 volts
minimum
-
. Sensor Power Dissipation
20 microwatts @ 4.2K for MI-470
Series. 25 microwatts @ 4.2K
for DT-500 Series. Dissipation
under other conditions is a
product of Sensor Excitation
Current and developed sensor
voltage.
M
9210-3 :
Input Voltage Range: 0 to 3 V
Resolution: 0.05 millivolts
Accuracy:
0.1 millivolts
Display Resolution: 5 digits.
Displays 0.0000 to 2.9999 volts.
Equivalent temperature accuracy
is a function of sensor type,
sensitivity and curve specification or Precision option.
9210-6:
Input Voltage Range: 0-6.5535V
Resolution: 0.1 millivolts
Accuracy: 0.2 millivolts
Display Resolution: 5 digits.
displays 0.0000 to 6.5535 volts.
equivalent temperature accuracy
is a function of sensor type and
sensitivity. Precision Option
required for TG-120 Sensors.
9210-1
9210 D i o d e Input Card
9210.4 INSTALLATION
The 9210 can be installed in the
91C/93C as either Input A or Input
B (or both with two options). The
9210 is factory installed if
ordered with a DRC-91C/93C
Temperature Controller or can be
field installed at a later date.
If field installation is required,
use the following procedure.
1. Set the POWER switch to OFF and
disconnect the power cord from
the unit. Remove the three top
panel screws and slide the panel
off.
Note on the calibration
cover the position of the Input
Card the 9210 will occupy.
WARNING
To prevent shock hazard, turn off
the instrument and disconnect it
from AC line power and all test
equipment before removing cover.
2. Remove
the four screws that
secure the calibration cover to
its clips and remove the cover.
3. If
an Input Card must be
removed, disconnect the wiring
harness mating connector by
lifting the locking tab on the
Input C a r d connector and gently
pulling on the body of the
wiring
harness
mating
connector.
4. Plug the new 9210 Input Card
into the A Input Card Slot 5 or
the B Input Card Slot 6 with the
component side to the left of
the unit as viewed
from the
front
Connect the wiring
harness mating connector to the
9210 making sure that the wiring
harness locking tab is seated
over the extended edge of the
wiring harness mating connector.
Verify that the wiring harness
is in place correctly by noting
that the “A” or “B” on the
.
9210-2
DRC-9 1C/93C
harness mating connector is
facing up (if it is not, review
the harness installation again).
Thread the wiring harness along
the rear edge of the unit and
slip it into the harness strain
relief on the rear panel.
5. Install the calibration cover by
reversing procedure 2.
6. Install the top panel.
9210.5 OPERATION
The Model
9210-3
Diode
Configuration provides the 10
microampere excitation current to
the sensor. The resulting sensor
voltage is digitized by a 16 bit
A/D converter with a resolution of
50 microvolts and a full scale
input voltage of 3.0000 volts (100
microvolts and 6.5535 volts for the
9210-6 configuration).
The
digitized value is converted to a
serial data string and transferred
to the main microprocessor using
optical isolation.
The sensor
voltage is also buffered and
transferred to the rear panel
MONITORS connector for external
monitoring as well as for control
selection.
For the 9210-3
configuration, it is multiplied by
1, for the 9210-6 configuration it
is multiplied
by
0.457771
(3.0000/6.5535).
9210.6 CALIBRATION
The 9210 was calibrated to
specification in the configuration
specified prior to shipment.
If
recalibration is needed, refer to
the following procedure.
The
following equipment is used to
calibrate the 9210 Diode Input
Card:
1. Digital Voltmeter/Multimeter
(RVM)
4½ digit resolution or
-
better.
COPYRIGHT 12/87 LSCI
Model DRC-91C/93C
-
2. Precision Standard Resistor
100 kilohms with a tolerance of
-±0.01% or better.
-
3. Precision
Voltage Source
capable of supplying a voltage
with an accuracy and resolution
of 100 microvolts out of 10
volts or better.
The unit should be allowed a one
hour warm-up time to achieve rated
specifications. Use the following
procedure to calibrate the 9210
Diode Input Card.
1. Remove the three top panel
screws and slide the panel cover
off
.
2. Set 10µA Current
-
Connect the
precision resistor across the A
(+I)and B (-1) pins of the five
pin input connector for the
input the 9210 occupies.
Connect the DVM plus lead to the
+I pin and the minus lead to the
-I pin.
Adjust the trimpot
marked
10µA
on t h e
calibration cover for the
appropriate Input Card
until
the voltage across the resistor
is 1.0000 ± 0.0001 volts.
3. Calibrate the
Buffered Sensor
Output Signal. Connect the DVM
plus lead to the +V Buffered
Sensor Output Signal pin for the
appropriate Input Card and the
minus lead to the -V pin on the
MONITORS connector. Connect the
precision voltage source across
the E (+V) and D (-V) pins of
the
five pin input connector
for the appropriate input. Set
the standard to 1.5000 volts and
adjust the trimpot marked B on
the calibration cover until the
DVM reads as close to 1.5000
volts as possible for the 9210-3
configuration and adjust the
value to 0.68666 volts for the
9210-6 configuration.
COPYRIGHT 12/87 LSCI
9210 Diode Input Card
the A / D Converter.
Verify that the Display selects
the desired Input Card and that
the units selected are V. Set
the standard to 1.5000 volts for
the 9210-3 and adjust the
trimpot marked A/D
until the
display reads 1.5000 V.
Check
linearity by inputting 2.0000
and 1.0000 volts and verify that
the unit displays those settings
within ± 0.0001 volts (5.0000
and 1.0000 volts for the 92106).
If this specification is
not met, check the Technical
Service Guide for further
instructions.
4. Calibrate
5. Install the top cover panel.
9210.7 SENSOR CURVE INFORMATION
Sensor Curve data for use with the
9210 Diode Input Card must be put
in table form consisting of voltage
and temperature points with the
voltage in ascending voltage order.
Refer to Section 4 of this manual
for a discussion of how the data
must be formatted for entry into
the unit over the remote interfaces
and to Appendix B for a discussion
of Precision Option curves and
examples of curves that would be
used with the 9210.
9210.8 REPLACEABLE PARTS
Included in this section is Figure
It includes the Model 9210
Diode Input Schematics, replaceable
parts list and
illustrated
component layout.
Refer to the
manual for ordering information.
9210-1.
9210-3
9215 Capacitance Input card
Model DRC-91C/93C
9 2 1 5 CAPACITANCE I N P U T C A R D O P T I O N
9215.1 INTRODUCTION
This section contains information
pertaining to the Model 921515/9215-150 Capacitance Input Card
Configurations
Specifications,
installation and operating instructions, a description of the
principle of operation, and
maintenance
information are
included. Section 9215.3 describes
some characteristics of Capacitance
sensors.
.
9215.2
DESCRIPTION
CATIONS
AND
SPECIFI-
The Model 9215 Capacitance Input
Card is designed to be installed in
a DRC-91C or DRC-93C to convert
either Input A or Input B to
accommodate Capacitance sensors.
when used to control temperature in
magnetic fields the capacitance
sensor is superior to other sensors
since the displacement current in a
capacitor is magnetic field
independent.
Accurate temperature
reading requires the use of another
type of sensor in zero magnetic
field. This accurate sensor can be
placed in the other Input Slot of
the DRC-91C/DRC-93C.
The 9215-15 configuration is used
with capacitance sensors with a
maximum of 30 nanofarads (for
example, Lake Shore CS-401 Series
Sensors).
The 9215-150 configuration will
accomodate Capacitance sensors of
up to 150 nanofarads (for example,
Lake Shore CS-501 Series).
The card can be configured by the
user as either a 15 nanofard (921515) or a 150 nanofarad (9215-150)
card by switches on the card.
Specifications for the Model 9215
COPYRIGHT 2 / 8 8 LSCI
Capacitance Input Card Configurations are given in Table 9215-1.
Table 9215-1. specifications of
the Capacitance Input Card
Display Resolution: 5 digits.
Display Units: Capacitance in
nanofarads.
TemperatureAccuracy:
A function of sensor sensitivity. See Table 9215-2. Unit
supports capacitance only.
Sign of Temperature Coefficient:
User Selectable by Switch on
on DRC-91C, Keys on DRC-93C
or via Computer Interface.
Magnetic Field Sensitivity:
< ±0.15% for B < 19 Tesla and
T > 4.2K. See Section 9215.3.
9215-15:
Sensor Excitation: 5 kilohertz
charging current.
Capacitance Range: 0 to 15 nF,
0-30 nF with reduced accuracy
Sensor (ordered separately):
CS-401 Series from LSCI or
or other Capacitance Sensor.
Resolution: 0.001 nF
Accuracy: ±0.25% of Full Scale
Range: 0.000 to 29.999 nF
Analog Output signal: 0.1 times
capacitance (nF) in volts
9215-150 :
Sensor Excitation: 1 kilohertz
charging current.
Capacitance Range: 0 to 150 nF
Sensor (ordered separately):
CS-501 Series from LSCI or
other Capacitance Sensor.
Resolution: 0.01 nF
Accuracy: ±0.25% of Full Scale
Range: 0.00 to 149.99 nF
Analog Output signal:0.02 times
capacitance (nF) in volts.
9215-1
9215 Capacitance Input Card
Table 9215-2 Typical Temperature Ranges and Sensitivities
DRc-91C/93C
Sensor Type
T (K)
c (nf)
DC/dT (Pf/K)
CS-401GR-A1
4.2
20.0
60.0
80.0
140.0
200.0
295.0
1.7609
2.0347
2.4227
2.3544
1.4847
0.9445
0.6307
20.77
15.30
2.42
9.14
-12.91
5.95
1.83
-
4.2
20.0
60.0
80.0
140.0
200.0
270.0
295.0
5.3155
6.1118
7.2357
7.0525
4.5379
2.9062
2.1054
1.9492
65.22
44.63
7.38
-25.61
-38.46
-18. io
7.07
5.55
(1184)
CS-4 01GR-B1
(1186)
CS-4 O1LG-B1
CS-401LG-C1
(1248)
CS-5012
(10002)
--
.3
4.2
20.0
60.0
80.0
140.0
200.0
270.0
295.0
11.1972
12.9423
15.3912
14.9303
9.3561
5.9762
4.3180
3.9989
137.
94.8
21.2
-60.7
-81.3
-37.1
-14.0
-12.2
4.4
20.0
60.0
80.0
140.0
200.0
270.0
295.0
6.5884
7.1334
9.0452
10.1940
14.0355
21.7233
91.0746
130.140
30.74
37.61
56.19
57.52
82.44
197.4
4025.
-1226.
Notes:
1.
2.
3.
9215-2
9215-15 configuration.
9215-150 configuration.
No Calibration Data Available
COPYRIGHT 2/88 LSCI
Model DRC-91C/93C
9215 Capacitance Input card
9215.3 NOTES ON CS-501 CAPACITANCE
SENSORS
9215.3.1
Short-Term Stability
The capacitance sensor provides
very stable temperature control
over long periods of time.
However, since an operational
“aging"phenomenon exists some care
must be exercised in their use.
The short-term (minutes to hours)
capacitance/temperature drift is
initiated by a thermal perturbation
of the sensor.
In order to minimize this shortterm drift, it is recommended that
approximately one hour be allowed
for the sensor to stabilize after
the initial cooldown. The shortterm drift is then on the order of
a few tenths of miIIikelvin/minute
at 4.2K, several millikelvin/minute
at 77K and one millikelvin/minute
at 305K.
For temperatures less
than 290K the short-term drift is
such that the equivalent temperature will decrease with time and
for temperatures above 290K will
increase with time.
9215.3.2
Thermal
Reproducibility
Cycling
and
Thermal cycling of capacitance
sensors can produce variations in
capacitance/temperature values
equivalent to several tenths of a
degree over the short term (days)
Thermal cycling over the long term
(weeks) can result in variations
that exceed a degree.
These
variations are always such that the
equivalent temperature increases
with time and with increased
cycling.
The reduced capacitance
C(T)/C(4.2K) for T<290K is stable
to within ±0.5K on the average.
Also these variations do not create
instabilities and do not impair the
sensors primary function as a
control device in magnetic fields.
They also are not seen within a
temperature cycle.
.
COPYRIGHT 2/88 LSCI
9215.3.3
Magnetic Field Dependency
Magnetic field sensitivity is less
than ±0.15 % at 4.2K and less that
±0.05 % between 77K and 305K for
fields up to 18.7 Tesla.
9215.3.4
Frequency Dependence
For frequencies between 1 and 5
kilohertz the frequency sensitivity
is as follows:
-0.18k/kilohertz at 4.2K
-1K/kilohertz at 77K
+0.06K/kilohertz at 305K
9215.4 INSTALLATION
The 9215 can be installed in the
DRC-91C/93C as either Input A or
Input B.
The card is factory
installed if ordered with a DRC91C/93C Temperature Controller or
can be field installed at a later
date.
If field installation is
required, use the following
procedure.
1. Set the POWER switch to OFF and
disconnect the power cord from
the unit. Remove the three top
panel screws and slide the panel
off.
Note -on the calibration
cover the position of the Card
will occupy.
WARNING
To prevent shock hazard, t u r n
off the instrument and disconnect it f r o m AC line power and
all test equipment before removing cover.
2. Remove
the four screws that
secure the calibration cover to
its clips and remove the cover.
Remove the two back panel
9215-3
9215 Capacitance Input Card
mounting clips that secure the
J11 blank cover plate to the
interface opening and remove the
plate.
(Note: some early DRC91Cs do not have the J11
opening.
Use the J9 8229
Scanner option opening.
If an
8229 is present move the 8229 to
the J10 RS-232 slot.
an Input Card must be
removed, disconnect the wiring
harness mating connector by
lifting the locking tab on the
Input Card connector and gently
pulling on the body of the
wiring harness mating connector.
3. If
4. Plug the new Input C a r d into the
A Input Card Slot 5 or the B
Input Card Slot 6 with the
component side to the left of
the unit as viewed
from the
front
Connect the wiring
.
harness mating connector to the
card making sure that the wiring
harness locking tab is seated
over the extended edge of the
wiring harness mating connector.
Verify that the wiring harness
is in place correctly by noting
that the “A” or “B” on the
harness mating connector is
facing up (if it is not, review
the harness installation again).
Thread the wiring harness along
the rear edge of the unit and
slip it into the harness strain
relief on the rear panel.
Thread the 9215 internal cable
along the inside edge of the
rear panel so that it won't
interfere with the installation
of the calibration cover or top
cover.
.
Be sure that the card is
centered in the slot. The harness
will have a tendency to push the
card forward and may in some
instances cause the card and
instrument to not behave properly.
-:
9215-4
DRc-91C/93C
5. Position the 9215 connector
plate in the appropriate opening
and secure it in place using the
screws provided.
6. Install the calibration cover by
reversing procedure 2.
7. Select
either the 9215-15 or
9215-150 configuration by
pressing
t h e appropriate
pushbutton switch.
8. Install the top panel.
9215.5 SENSOR CONNECTIONS
The 9215 connector plate supplies
two independent dual isolated BNC
connectors for the sensor connections. A four lead measurement is
used to minimize the effect of
series resistance on the capacitance measurement.
Since the
capacitance sensor is non-polarized, one pair should be used for the
current connections and the other
pair for the voltage connections.
The pin contact of the connector is
+ and the socket
-.
9215.6 SELECTION OF THE SIGN OF THE
TEMPERATURE COEFFICIENT
The temperature coefficient of some
Capacitance Sensars can be positive
or negative depending on the
temperature range.
The 9215 Card
produces a voltage proportional to
the Capacitance which is sent to
the control circuitry of the DRC91C/93C to be compared to a user
selected setpoint. For control to
operate properly, the sign of the
voltage must reflect the temperature coefficient of the sensor. It
is necessary for the user to
determine which range the sensor is
in and to inform the controller of
the sign of the temperature
coefficient. This is accomplished
on the DRC-91C by a switch (switch
1 of the SENSOR ID) on its rear
COPYRIGHT 2/88 LSCI
Model DRC-91C/93C
panel and on the DRC-93C by a
sequence of key strokes from its
front panel. Also the Sign of the
temperature coefficient can be
entered via the computer interface
using the AC1C2 or BC1C2 command.
selection of Temperature
Coefficient Sign on the DRC-91C
9215.6.1
The sign to be used on the Temperature Coefficient of the capacitance
is selected using Switch 1 of the
appropriate SENSOR ID located on
the rear panel of the DRC-91C.
When Switch 1 of the SENSOR ID is
closed the Temperature Coefficient
is Positive. When Switch 1 of the
SENSOR ID is open, the Temperature
Coefficient is Negative.
9215.6.2 Selection of Temperature
Coefficient Sign on the DRC-93C
When a 9215 Capacitance Input Card
is installed, pressing the SENSOR
key will display for the appropriate channel either ±15-15 or
±15-50; the -15 for the 9215-15
configuration or -50 for the 9215150 configuration.
The (±) sign
indicates whether the Temperature
Coefficient is positive or negative. The plus (+) means that the
Temperature Coefficient is positive. The minus (-) means that the
Temperature Coefficient is negative.
Select the Temperature Coefficient
sign from the front panel by using
a combination of the SENSOR key,
SCAN
key and the
key and
key as follows:
1. Press and hold the SENSOR key.
2. While holding down the SENSOR
key, press the SCAN
key.
You may now let up on the SENSOR
key.
3. To change the sign if in the
COPYRIGHT 2/88 LSCI
9215 Capacitance Input card
upper display hit the
key
while still holding down the
SCAN
key.
Similarly, to
change the sign if in the lower
display hit the
key while
still holding down the SCAN
key.
4. Now let up on the
key (or
key) and then the SCAN
key.
You should press the SENSOR key to
make sure that the sign is as
desired.
9215.6.3 Selection of the Sign of
the Temperature Coefficient via the
Computer Interface
To select the sign
ture coefficient
interface, check
BC1C2 commands in
manual.
of the temperavia the IEEE
the AC1C2 and
the instrument
9215.7 PRINCIPLE OF OPERATION
The 9215-15 configuration provides
a charging current switched at a
frequency of 5 kilohertz.
The
frequency is precisely controlled
by a crystal oscillator.
The
operation of the 9215-150 is
identical except that the frequency
is 1 kilohertz.
The charging
current produces a sawtooth voltage
waveform with a peak-to-peak
voltage of about 7 volts. Another
voltage of precise amplitude is
generated which has a duty cycle
dependent on the charging time of
the capacitor.
This waveform is
averaged and filtered to produce a
positive DC voltage proportional to
the capacitance.
This Dc voltage
is sent to a 16 bit A/D converter
on the card. The A/D converter has
a resolution of 50 microvolts and a
full scale input voltage of 3.0000
volts. With the 9215-15 Configuration the 3.0000 volts corresponds
to a capacitance of 30 nanofarads;
and on the 9215-150 configuration
to 150 nanofarads.
The digitized
9215-5
9215 Capacitance Input card
value is converted to a serial data
string and transferred to the main
microprocessor using optical
isolation.
A relay on the Card configures the
sensor voltage as negative or
positive based on the temperature
coefficient sign selected by the
That
user (Section 9215.5).
voltage is buffered and transferred
to the rear panel MONITORS connector for external monitoring as well
as to the main board control
circuitry.
9215.8 CALIBRATION
The 9215 was calibrated to specification prior to shipment. The card
meets specification for operation
either in the 9215-15 or 9215-150
configuration by simply pressing
the switches located on the card.
This Section provides information
to permit recalibration if needed.
NOTE:
Calibration
for zero
capacitance may be required to meet
accuracy specifications if your
sensor lead capacitance or stray
capacitance is excessive.
The following equipment is used to
calibrate the 9215 Capacitance
Input Card:
1. Digital
-
(DVM)
better.
Voltmeter/Multimeter
4½ digit resolution or
-
2. Precision Standard Capacitors
10 nanofarad and 100 nanofarad
with tolerance
better.
3. Precision
of
±0.1%
or
-
Voltage Source
capable of supplying a voltage
with an accuracy and resolution
of 100 microvolts out of 10
volts or better.
9215-6
DRC-91C/93C
The unit should be allowed a one
hour warm-up time to achieve rated
To begin remove
specifications.
the three top panel screws and
slide the panel off. The procedure
is divided into three parts as
follows.
1. Calibration
verter.
of
the
A/D
Con-
2. Zero calibration.
3. Span Calibration.
The zero and span calibration is
done with the instrument and system
wiring configured as it will be
used.
This will provide optimum
accuracy because lead and stray
capacitance will be taken into
account.
9215.8.1 A/D Calibration
1. Locate DIP switch package SIASwitch 2.
Under normal opera-
tion this switch is CLOSED(1).
Change this switch to the
OPEN (0) position.
2. Connect the DVM plus lead to the
+V Buffered Sensor output Signal
pin for the appropriate Input
Card and the minus lead to the
-V pin on the MONITORS connector.
Connect the precision
voltage
source across the E
(+V) and D (-V) pins of the
five pin input connector for the
input corresponding to the
Capacitance Card.
3. Set
the
volts.
standard
to
1.5000
4. Verify that the Display indi-
cates
Card.
the
Capacitance
Input
5. Adjust the trimpot marked A/D
until the display reads 15.000nF
for the 9215-15 or 75.00nF for
the 9215-150.
Check linearity
by inputting 2.0000 and 1.0000
COPYRIGHT 2/88 LSCI
9215 Capacitance Input Card
Model DRC-91C/93C
volts and v e r i f y that the u n i t
displays 20.000 and 10.000nF
w i t h i n ±0.001nF f o r the 9215-15
or 100.0 and 50.0nF within
_
±0.01nF f o r the 9215-150.
6. Return
S1A
-
Switch 2 t o the
CLOSED 1) position.
9215.8.2
Zero Calibration
1. Be sure t h a t the leads are i n
the configuration w h i c h w i l l be
used in your system. Detach the
capacitance sensor.
2. Verify t h a t the Display indic a t e s t h e Capacitance Input
Card.
3. A d j u s t the trimpot marked ZERO
so that the display reads 0.000
on the 9215-15 o r 0.00 on the
9215-150.
9215.8.3
Span Calibration
1. Be sure t h a t the leads are i n
the configuration which w i l l be
used in your system. A t t a c h the
standard capacitor i n place of
the capacitance sensor.
2. V e r i f y that the Display indicates t h e Capacitance Input
card.
3. A d j u s t the trimpot marked SPAN
so that the display reads the
value of the standard capacitor.
9215.9 REPLACEABLE PARTS
Included in this section is Figure
9215-1. I t includes the Model 9215
C a p a c i t a n c e I n p u t Schematics,
replaceable parts list and illustrated component layout. R e f e r
t o the manual for ordering informtion.
COPYRIGHT 2/88 LSCI
9215-7
Figure 9215-1. Model 9215 Capacitance Input Card
REPLACEABLE P A R T S L I S T
ITEM
NO
LSCl
Part
Number
Qty
-
9 2 1 5 C A P A C I T A N C E INPUT CARD
Description
MFR
MFR PART
NO
c2,3,4
c5
101-034
101-025
3
1
CAP,PP,1.0MF,100V
CAP,PP,.33MF,100V
FDYNE
FDYNE
MPP2X-1.0-100-10
MPP-11.33MFD
P2
106-142
1
CONNECTOR,
( I C T O BP
6 POST LOCKING HEADER
MOL
2420-09-75-1061
Q1
102-072
2
TRANSISTOR,PNP,SIGNAL
s1
105-649
1
SWITCH,2
u1
u2
u4
104-051
1 0 2 - 075
104-461
104-099
104-460
104-001
104-010
102- 020
104 087
1 0 4 - 078
104-355
1
1
IC, T I M E R
MOSFET,N CHANNEL
I C , A/D CONVERTER
IC, P - S SHIFT REGISTER
U5,6,17
u7
U8
u9
u10
U13,18,
20
u14
u15
U16
U19
-
102-037
104-054
104-101
104-356
1
3
1
1
1
1
1
1
3
1
1
1
1
POS,4
POLE
I C , F / V CONVERTER
REGULATOR,-5
I C , D U A L OP AMP
IC, S W I T C H E D C A P A C I T O R
I C , OPTOCOUPLER
VOLTAGE REFERENCE,
IC, OSCILLATOR
IC, D E C A D E COUNTER
I C , OPTOCOUPLER
10V
213906
EGC
2XMTA7.5(NONE)
4UGRP
I SL
ICM7555IPA
VN0535N2
ICL7104-16CPL
C D 4 0 2 1BCN
ICL8068ACPD
ISL
ISL
PMI
NAT
MOT
TDYN
LT
GI
LT
EPS
GI
Op07e
L M 3 3 1N
79105
TSC913A
LT1043CN
740L6000
REF-01EN8
S G - 1 0 - 10 K A
4029CBN
740L6010
Model DRC-91C/93C
9220 Input Card
9220 USER CONFIGURABLE I N P U T C A R D OPTION
9220.1
INTRODUCTION
This section contains information
pertaining to the Model 9220 Diode
and Platinum User Configurable
Input Card.
Included is a
description, specifications,
installation, operation and
maintenance information.
9220.2
DESCRIPTION
The Model 9220 Diode and Platinum
Input Card is designed to be
installed in a DRC-91C or DRC-93C
to convert either the Input A or
Input B (or both with two options)
to accommodate either diode or
positive temperature coefficient
sensors such as platinum or
rhodium-iron.
The 9220-3 configuration is
e q u i v a l e n t t o t h e 9210-3
configuration described earlier.
The 9220-6 configuration is
e q u i v a l e n t t o t h e 9210-6
configuration.
The 9220-P2 converts either InputA
or B (or both with two options) to
accommodate 100 ohm platinum RTD's
which conform to DIN 43760
tolerances + 0.1K, have
interchangeability of 0.1% at 0 C
and a temperature coefficient of
0.00385/°C from 0 to 100 C. This
card may also be configured as a
9220-P3 (1000 ohm platinum) or
9220-R1 (rhodium-iron) input card.
an
9220.3
SPECIFICATIONS
Specifications for the Model 9220
User Configurable Input Card are
given in Table 9220-1 of this
manual. The card can be configured
as a 9220-3 or 9220-6 diode card, a
9220-P2 or 9220-P3 platinum card or
a 9220-R1 rhodium-iron input card.
COPYRIGHT 12/87 LSCI
Table
9220-1.
InputCard
9220
Configurable
9220-3: See 9210-3 specifications.
9220-6: See 9210-6 specifications.
Sensor (ordered separately):
Platinum RTD sensor. PT-100
series or any other 100 ohm or
1000 ohm platinum sensor.
27 ohm rhodium-IRON sensor,
See Lake Shore Sensor brochures.
Temperature Range: Dependent on
Sensor. See Sensor brochure.
RTD Sensor Power Dissipation:
Depends on Sensor Resistance.
Dissipation is the product of
sensor excitation current squared
and the Sensor resistance.
9220-P2: 100 ohm platinum
Current Excitation: lmA(±0.005%)
Resistance Range: 0.00-299.99.
Resolution: 0.005 ohms
Accuracy: 0.01 ohms
Display Resolution: 5 digits;
Displays 0.00 to 299.99 ohms.
9220-P3: 1000 ohm platinum
Current Excitation: 0. 1mA(±0.005%)
Resistance Range: 0 . 0 to 2999.9
Resolution: 0.05 ohm
Accuracy:
0.1 ohm
Display Resolution: 5 digits.
Displays 0.0 to 2999.9 ohms.*
9220-R1: 27 ohm platinum
Current Excitation: 3 mA(±0. 005%)
Resistance Range: 0.000 to 99.9992
Resolution: 0.003 ohm
Accuracy: 0.003 ohm
Display Resolution: 5 digits.
Displays 0.000 to 99.999 ohms.
*Equivalent temperature accuracy
is a function of sensor type,
.sensitivity and Precision Option.
9220-1
9220 Input Card
9220.4
INSTALLATION
The 9220 can be installed in the
91C/93C as either Input A or Input
B (or both with two options). The
9220 is factory installed if
ordered with a 91C or 93C
Temperature Controller or can be
field installed at a later date.
If field installation is required,
use the following procedure.
WARNING
Model DRC-91C/93C
harness mating connector is
facing up (if it is not, review
the harness installation again).
Thread the wiring harness along
the rear edge of the unit and
slip it into the harness strain
relief on the rear panel.
5. Install the calibration cover by
reversing procedure 2.
6. Install the top panel.
9220.5
1. Set the POWER switch to OFF and
disconnect the power cord from
the unit. Remove the three top
panel screws and slide the panel
off.
Note on the calibration
cover the position of the Input
Card the 9220 will occupy.
2. Remove
the four screws that
secure the calibration cover to
its clips and remove the cover.
3. If
an Input Card must be
removed, disconnect the wiring
harness mating connector by
lifting the locking tab on the
Input C a r d connector and gently
pulling on the body of the
wiring
harness
mating
connector.
4. Plug the new 9220 Input Card
into the A Input C a r d Slot 4 or
the B Input Card Slot 5 with the
component side to the left of
the unit as viewed
from the
Connect the wiring
front
harness mating connector to the
9220 making sure that the wiring
harness locking tab is seated
over the extended edge of the
wiring harness mating connector.
Verify that the wiring harness
is in place correctly by noting
that the “A” or “B” on the
.
9220-2
OPERATION
The
9220-3
and
9220-6
configurations are equivalent to
9210-3
and
9210-6
the
configurations in terms of
operation.
The Model 9220-P2 Configuration
provides the 1 milliampere
excitation current to the platinum
sensor (the 9220-P3 supplies 0.1
milliampere and the 9220-R1
The
supplies 3 milliamperes).
resulting sensor voltage is
amplified by a factor of -10
(negative 10) and digitized by a 16
bit A/D converter with a resolution
of better than 100 microvolts out
of 3.0000 volts full scale. The
digitized value is converted to a
serial data string and transferred
to the main microprocessor using
optical isolation.
The amplified
(-10) sensor voltage is transferred
to the J3 MONITORS connector for
external monitoring.
9220.6
CALIBRATION
The 9220 was calibrated to
specification prior to shipment.
If recalibration is needed, refer
to the following procedure.
The
following equipment is used to
calibrate the 9220 Input Card:
1. Digital
-
(DVM)
better.
Voltmeter/Multimeter
4½ digit resolution or
COPYRIGHT 9/87 LSCI
Model DRC-91C/93C
9220 Input Card
-
2. Precision Standard Resistor
1 kilohms for 9220-P3 or 100
ohms for 9220-P2 and 9220-R1
with a tolerance of +/- 0.01% or
better.
-
3. Precision
Voltage Source
capable of supplying a voltage
with an accuracy and resolution
of 10 microvolts out of 1 volt
or better.
The unit should be allowed a one
hour warm-up time to achieve rated
specifications
.
Refer to the 9210 section for the
calibration procedure for the 92203 and 9220-6 configurations.
Use the following procedure to
calibrate the 9220-P2, -P3 and -R1
Configurations
.
1. Remove
the three top panel
screws and slide the panel off.
2. set 100 µA,
1mA, 3mA Current
Connect
t h e appropriate
precision resistor across the A
(+I) and B (-1) pins of the five
pin input connector for the
input (J1 or J2) the 9220
occupies. Connect the DVM plus
lead to the +I pin and the minus
lead to the -I pin. Adjust the
trimpot marked 1mA (for -P2) on
the
calibration cover (100µA
for -P3, 3mA for -R1) for the
appropriate Input Card until the
voltage across the resistor is
equal to the sensor current
times the resistance ± the
tolerance of the resistor.
3. Calibrate
the Input -10
Amplifier -Connect the DVM plus
and minus leads to the + V and
-V Sensor Output Signal pins for
the appropriate Input C a r d of
the J3 MONITORS connector.
Connect the precision voltage
source across the E(+V) and D(V) of J1 INPUT A or J2 INPUT B
COPYRIGHT 12/87 LSCI
for the appropriate input and
set the standard to 0.0000
volts.
Adjust the
trimpot
marked
AMP
z
on the
calibration cover until the DVM
reads as close to 0 volts as
possible.
Set the standard to
0.2500 volts and adjust the
trimpot marked AMP S on the
calibration cover until the
voltage reads -2.5000 volts.
the A/D ConverterVerify that the Display Sensor
is the desired Input Card and
that the units are ohms.
Set
the standard to 0.2700 volts and
adjust the trimpot marked A/D
until the display reads 270.00
ohms (for the 9220-P3 an input
of 0.2700 volts results in a
display of 2700.0 ohms and for
the 9220-R1 an input of 0.2700
volts results in a display of
81.00 ohms). Check linearity by
inputting 0.2000 and 0.1000
volts and verify that the unit
displays 200.00 and 100.00 ohms
within +/0.01
ohms (or
equivalent for the 9220-P3 and
9220-Rl) .
4.Calibrate
5. Install the top panel.
9220.7
SENSOR CURVE INFORMATION
Sensor Curve .data for use with the
9220 RTD Configurations must be put
in table form consisting of voltage
and temperature points with the
voltage in ascending voltage order.
Since the 9220 raw data would be in
resistance form, it must be
converted prior to entering. Refer
to Section 4 of this manual for a
discussion of how the data must be
converted and formatted for entry
into the unit Over the remote
interface and to Appendix B for a
discussion of Precision Option
curves and examples of curves that
would be used with the 9220.
9220-3
9220 Input Card
9220.8
Model DRC-91C/93C
REPLACEABLE PARTS
Included in this section is Figure
9220-1. It includes the Model 9220
input schematics, replaceable parts
list and illustrated component
layout.
Refer to the manual for
ordering information.
9220-4
COPYRIGHT 9/87 L S C I
Model 9220-1. Model 9220 User Configurable Input Card
REPLACEABLE PARTS L I S T
ITEM
NO
LSCI
Part
Number
QtY
-
9 2 2 0 ANALOG INPUT CARD
Description
MFR
MFR PART NO
101-034
6
CAP,PP,1.0MF,100V
FDYNE
MPP2X-1.0-100-10
101-025
1
CAP,PP,.33MF,100V
FDYNE
MPP-11.33MFD
P2
106-142
1
CONNECTOR, ( 1 C T O B P )
6 POST LOCKING HEADER
MOL
2420-09-75-1061
Q1
102-072
1
TRAISISTOR,PNP,SIGNAL
s1
105-649
1
SWITCH,2 POS,4
INTERLOCKING
u1
u2
U3,17
u4,5,15
U6,8,9
u7
U10-12
U13
102-074
104-005
102-043
104-001
104-355
104-356
104-099
104-461
104-460
102-020
104-051
104-078
1
1
2
3
MOSFET,P CHANNEL
I C , OP-AMP
VOLTAGE REFERENCE,6.95V
I C , OP A M P
I C , OPTOCOUPLER
IC, O P T O C O U P L E R
I C , P - S SHIFT R E G I S T E R
I C , A/D CONVERTER
IC, A / D R E F E R E N C E
REGULATOR, - 5 V
IC, TIMER
I C , SWITCHED CAPACITOR
c4,5,11
17,18,28
C l 6
U14
U16
U18
U19
3
1
3
1
1
1
1
1
POLE
2N3906
EGC
2XMTA7.5(NONE)
4UGRP
SIL
3N163
Lm308
LR399H
OP07EP
740L6000
740L6010
CD4021BCN
IC L 7 1 0 4 - 1 6 C P L
ICL8068ACPD
79LO5CT
ICM7555IPA
LTC1043
NAT
PM I
GI
GI
ISL
ISL
MOT
ISL
LT
REPLACEABLE PARTS L I S T
-
9 2 2 0 ANALOG I N P U T CARD
LSCI Part
Number
Qty
101- 0 3 4
6
CAP,PP,1.0MF,100V
FDYNE
MPP2X-1.0-100-10
101-025
1
CAP8PP,.33MF,100V
FDYWE
MPP-11 .33MFD
P2
106-142
1
CONNECTOR,
MOL
2420-09-75-1061
Q1
102-072
1
TRANSISTOR,PNP,SIGWAL
S1
105-649
1
S W I T C H , 2 POS,4
INTERLOCKING
u1
102-074
104-005
102-043
104-001
104-355
104-356
104-099
104-461
104-460
102-020
104-051
104-078
1
1
2
3
MOSFET,P CHANNEL
IC, OF-AMP
VOLTAGE REFERENCE,6.95V
I C , OP AMP
I C , OPTOCOUPLER
I C , OPTOCOUPLER
IC, P-S SHIFT REGISTER
I C , A/D CONVERTER
I C , A/D R E F E R E N C E
REGULATOR, - 5 V
IC, TIMER
I C , SWITCHED CAPACITOR
ITEM
NO
c4,5,11
17,18,28
C16
u2
U3,17
u4,5,15
U6,8,9
u7
UIO-12
U13
U14
U16
U18
U19
3
1
3
1
1
1
1
1
Description
(IC
TO BP)
6 POST LOCKING HEADER
POLE
MFR
M F R P A R T 10
2N3906
EGC
2XMTA7.5(NONE)
4UGRP
SIL
3N163
Lm308
LM399H
OP07EP
740L6000
740L6010
CD4021BCN
ICL7104-l6CPL
ICL8068ACPD
79L05CT
ICM755SIPA
LTC1043
NAT
PMl
GI
GI
ISL
I SL
MOT
ISL
LT
9305
9305.1
THERMOCOUPLE I N P U T C A R D
INTRODUCTION
This section contains information
pertaining to the Model 9305
Thermocouple Input Card. Included
is a description and information on
specifications,
installation,
operation and field calibration.
9305.2
CATIONS
9305.2.1
DESCRIPTION AND Specifi-
Description
The Model 9305 Thermocouple Input
Card is designed to be installed in
a Lake Shore DRC-91C or DRC-93C
Temperature Controller. It allows
either Input A or Input B (or both
with two cards) to accommodate
thermocouple sensors. Chromel vs.
Gold-0.03
at.% Fe, chromel vs.
Gold-0.07 at.% Fe, E, K, and T
thermocouples are supported with
internal curves that enable the
controllers t o operate in
temperature units C, F and K, as
well as voltage in millivolts.
The 9305 utilizes a secondary
temperature sensor to monitor the
R e f e r e n c e Junction
(room)
temperature and provide curve
compensation.
The Reference
Junction Compensation can be
disabled so the 9305 can be used
with external compensation
techniques.
Offset Adjustment is provided
adjacent to the Terminal Block to
compensate for thermocouple
variations
and
system
irregularities.
An
COPYRIGHT 6/88 LSCI
9305.2.2
specifications
Specifications for the Model 9305
Thermocouple Input Card are given
in Table 9305-1.
The temperature range for each type
of thermocouple is given in Table
9305-2.
9305.3 INSTALLATION
The 9305 can be installed in a DRC91c or a DRc-93c as either Input A
or Input B. The 9305 is installed
prior to shipment if ordered with a
controller.
If only one card is
ordered and its input is not
specified when ordered, it is
installed in Input A. When a card
is ordered for field installation,
the Input Card Configuration Table
located on the first page of the
Instruction Manual should be
updated to keep documentation
current.
Use the following procedure for the
installation of the 9305
Thermocouple Input Card.
WARNING
To prevent shock hazard, turn off
theinstrument and disconnect it
from Ac line power and all test
equip
1.
nt before removing cover.
Set the POWER switch to OFF and
disconnect the power cord from
the unit. Remove the three top
panel screws and slide the
panel off.
Note from the
calibration cover the position
of the Input Slot the 9305 will
occupy.
9305-1
9305 Thermocouple Input Card
Table 9305-1.
Model.
DRC-91C/93C
Specifications, Model 9305 Thermocouple Input Card
Input Voltage Range: Room Temperature Compensated: -10 to +10
millivolts. Uncompensated: -15 to +15 millivolts.
Temperature Range:
9305-2.
Depends on Thermocouple type.
Refer to Table
Thermocouples (Ordered Separately): Chromel vs. Au-0.03 at.% Fe,
Chromel vs. Au-0.07 at.% Fe, Chromel vs. Constantan (E),
Chromel vs. Alumel (K), and Copper vs. Constantan (T)
.
Thermocouple-EMF Tables: Curve tables are stored in the controller
and accessed through normal curve selection. The curves are
normalized to zero degrees Celcius and listed in Table 9305-4.
InputResistance: Greater than 109 ohms
Terminal B l o c k and Room Temperature Compensation: A secondary sensor
is installed in the rear panel mounted Terminal Block to measure
the Reference Junction Temperature. Compensation can be enabled or
disabled.
Offset Adjustment:
Terminal Block.
One-point hardware adjustment built into the
Electroniic Resolution:
1 microvolt
Electronic Accuracy: ±3 µV for -10 to +10 millivolts, ±5 µV up to
the -15 and +15 millivolt full scales.
Depends on conformity of the thermocouple to it's
overall-cy:
standard curve and system configuration.
Controllability:
Typically ±0.2K in a properly designed system.
Display Resolution: 5 digits. Compensated and uncompensated voltage
in millivolts from 0.000 to ±15.000 or temperature in Celcius,
Fahrenheit and Kelvin.
Note: When displaying millivolts, the unit V is shown.
Card processes an analog voltage output
signal 200 times the thermocouple voltage. The instrument generates
setpoint voltage based on the voltage or temperature entered by the
user. If compensation is enabled, the setpoint voltage is modified
to reflect the compensation required. Real-time analog comparison
of these two voltages provides the required control error signal.
Temperature Control Signal:
9305-2
COPYRIGHT 6/88 LSCI
Model DRC-91C/93C
Table 9305-2.
Thermocouple
Type
chromel vs.
Au-0.03 at.% Fe
chromel vs.
Au-0.07 at.% Fe
E
K
T
9305 Thermocouple Input Card
9305 Thermcouple Input card Temperature Ranges
compensated
4
- 325 K
- 325 K
3 - 425 K
3
3
- 325 K
3 - 475 K
3
- 485 K
3.
If the 9305 is to replace an
existing Input Card, unplug the
Input Card which is to be
replaced.
Disconnect the
wiring harness mating connector
by lifting the locking tab on
the Input Card and gently
pulling on the body of the
wiring
harness
mating
connector.
Attach t h e Thermocouple
Terminal Block into the
Alternate Connector Slot J9 if
the Card is Input A or in
Alternate Connector Slot J11 if
the Card is Input B with the
wires facing the input card
(Slots are shown in Figure
3.2). Uncovering the Connector
Slot may require the removal of
a plastic cover plate. If the
JF mating connector on the main
board
interferes
with
installation of the Terminal
Block remove it by lifting the
locking tab and gently pulling
Be
the body of the connector.
sure to lock the JF mating
- 325 K
1.4
- 525 K
Remove the four screws that
secure the calibration cover to
its clips and remove the cover.
COPYRIGHT 6/88 LSCI
4
1.4
2.
4.
Uncompensated
3
- 575 K
- 575 K
connector securely in place
after this step is complete.
5.
Connect the wiring harness from
the Terminal Block to the
(bottom) P3 Connector on the
9305 Card. Also connect the J1
(Input A) or J2
(Input B)
wiring harness mating connector
to the (top) P2 Connector on
the 9305 Card. Make sure that
the wiring harness locking tab
is seated over the extended
edge of the wiring harness
mating connector.
Plug the 9305 into the
appropriate Input Card Slot
with the component side facing
to the left of the unit as
viewed from the front.
Make
sure the card is thoroughly
seated. Verify that the wiring
harness is in place correctly
by noting that the “A” or “B”
on the harness connector is
facing up (if it is not, review
the harness installation
again)
.
6.
Replace the calibration cover
making sure to align the cards
so that their respective
9305-3
9305 Thermocouple Input card
adjustment trimpots are
accessible through the cover.
Place the cover on top of the
cover clips and start the
screws.
Carefully move any
misaligned cards to their
proper position and tighten the
cover screws. Replace the top
panel and three top panel
screws.
9305.4 SENSOR ATTACHMENT
Thermocouple leads are attached to
the Terminal Block by aluminum
screws.
Be sure to tighten the
terminal screws carefully.
Loose
connections will result in unstable
readings and control.
The leads
must be connected with the proper
polarity or the 9305 will not
operate properly.
The positive
terminal of the terminal block is
marked with a plus sign and should
correspond with the positive
thennoelement listed for each type
of thermocouple in Section 9305.5.
9305.5 NOTES ON THERMOCOUPLES
Lake Shore's 9305 Thermocouple
Input C a r d supports the Chromel vs.
K,
and T type
Gold,
E,
thermocouples.
9305.5.1 Gold-Chromel Thermocouples
The Gold Chromel thermocouple
consists of a Gold(Au)-0.03 at.%,
or 0.07 at.% Iron(Fe) alloy as the
negative thermoelement and a Ni-Cr
alloy (Chromel) as the positive
thermoelement (KP). This type of
thermocouple can be used at very
low temperatures, even below 10 K.
9305.5.2 Type E
Thermocouples
The ASTM (American Society for
Testing and Materials) designation
type E indicates a thermocouple
pair consisting of a Ni-Cr alloy
9305-4
Model DRC-91C/93C
(Chromel) as t h e positive
thennoelement (EP) and a Cu-Ni
alloy (constantan) as the negative
thermoelement
(EN).
This
thermocouple has the highest
sensitivity of the three ASTM
standard thermocouple types
typically used for low temperature
applications, types E, K, and T.
The E thermocouple is the best
choice for temperatures down to
about 40 K. It is recommended for
use in oxidizing environments, or
in sulphurous or reducing
atmospheres. It should not be used
in environments that promote
corrosion.
9305.5.3 Type K Thermocouples
The ASTM designation type K
indicates a thermocouple pair
consisting of a Ni-Cr alloy
(Chromel) as t h e positive
thennoelement (KP) and a Cu-A1
alloy (Alumel) as the negative
thermoelement (KN). It should not
be used in sulphurous or reducing
atmospheres, or in environments
that promote corrosion.
9305.5.4 Type T Thermocouples
The ASTM designation type T
indicates a thermocouple pair
consisting of Cu (Copper) as the
positive thermoelement (TP) and a
Cu-Ni alloy (Constantan) as the
This
negative thermoelement (TN)
type of thermocouple may be used in
vacuum as well as oxidizing or
reducing environments down to about
90 K.
At temperatures below 80 K
the thermoeletric properties of the
positive thermoelement (TP) are
very dependent on the impurity of
iron.
.
9305.6
PRINCIPLE OF OPERATION
The 9305 Thermocouple Input Card
has the capability of interfacing 5
different thermocouple types in
COPYRIGHT 6/88 LSCI
9305 Thermocouple Input Card
Model DRC-91C/93C
Table 9305-2 to the Lake Shore
DRC-91C and DRC-93C Temperature
Controllers over their respective
temperature ranges.
The thermocouple voltage is
amplified by 100 by a circuit which
is attached to the Terminal Block
The thermocouple voltage is further
amplified by a factor of 2
(tunable) by the Control Amplifier
on the 9305 Thermocouple Input
.
card.
The amplified signal is sent to the
main board analog control circuitry
and can be accessed from the
Buffered Output line of the J3
Monitor
Connector on the
controllers back panel.
In
addition,
the
amplified
thermocouple voltage is applied to
a 15 bit A/D converter on the
Thermocouple Input Card so that
digitized thermocouple voltage can
be sent to the main board
microprocessor.
The Thermocouple
A/D
converter has an auto-zero
function which means that the only
calibration required is for the
relative gain.
secondary diode temperature
sensor is attached to the Terminal
Block to monitor the reference
junction temperature needed for
Reference Junction Compensation. A
constant current source on the 9305
Card is applied to the Secondary
Sensor.
A 15 bit A/D converter
on the 9305 Card digitizes the
secondary sensor voltage and sends
the data to the main board
microprocessor. The microprocessor
on the main board of the controller
calculates the reference junction
temperature.
The reference
junction temperature is used in
compensation to account for the
difference between room temperature
and the normalization temperature
of the curves, zero degrees
Celcius.
A
COPYRIGHT 6/88 LSCI
Offset Adjustment is provided
adjacent to the Terminal Block.
This adjustment will zero out small
voltage offsets that result from
sensor lead attachment and
differences from the internal
curve.
An
9305.6.1
Display Operation
Digitized thermocouple and
secondary sensor voltages on the
9305 card are sent to the main
board of the controller.
The
secondary sensor temperature is
computed from its voltage and a
thermocouple voltage corresponding
to the secondary sensor temperature
is calculated.
If correction is
selected, the compensation value is
added to the thermocouple voltage.
Corrected voltage in millivolts is
then used as a display value or
converted to Celcius degrees,
Fahrenheit degrees, or Kelvin for
display.
9305.6.2
Control Operation
Control operation begins when the
operator enters a Setpoint voltage
in millivolts. If the Setpoint is
in temperature, the main board
computes an equivalent voltage
using the built-in Thermocouple
The main
board
t a b1e
microprocessor then checks to see
if Reference Junction Compensation
is enabled.
.
If the Reference Junction
Compensation is disabled, a signal
which is 200 times the digital
value of Setpoint voltage is
applied to the Setpoint D/A to
obtain the Setpoint voltage for
control.
If t h e Reference Junction
Compensation is enabled, a voltage
corresponding to the Terminal Block
temperature is subtracted from the
Setpoint voltage.
A signal which
is 200 times the digital value as
9305-5
9305 Thermocouple
Input C a r d
M o d e l DRC-91C/93C
calculated above is applied to the
Setpoint D/A to obtain the Setpoint
voltage for control.
The control analog hardware
compares the Setpoint voltage from
the Setpoint D/A converter and the
amplified thermocouple voltage to
obtain an error signal. The error
signal is minimized through the PID
control circuitry.
9305.7 OpeRATING
9305.7.1
Selection
INSTRUCTIONS
Thermocouple
Curve
Thermocouple Tables are chosen by
selecting one of the Curves numbers
given in Table 9305-3.
The
instruments detect the presence of
the Thermocouple Input Card and
then select the proper Thermocouple
Table rather than the Standard
Diode or Resistance curve listed in
the Instruction Manual.
The SENSOR ID Switches on the rear
panel of the DRC-91C are used to
select curves as described in
Instruction Manual Section 2.3.8.
Curve selection can also be made
over Computer Interface as
described in Section 4.8.5.
On the DRC-93C the Thermocouple
Table is selected by selecting the
Curve # as described in the DRC-93C
Instruction Manual Section 3.9.1.
Curve selection can also be made
over Computer Interface as
described in Section 4.8.9.
9305.7.2
selection of Reference
Junction COmpensation on the
DRC-91c
Whether or not Reference Junction
Compensation is used is selected
using Switch 3 of the SENSOR ID.
When Switch 3 of the SENSOR ID is
closed (1) the Reference Junction
9305-6
C o m p e n s a t e d value of t h e
thermocouple voltage is displayed.
When Switch 3 of the SENSOR ID is
open (0), the actual (measured)
thermocouple
voltage
or
uncompensated temperature is
displayed. With the 9305 selected
as the Display Sensor, hold the
LOCAL key to show card type and
curve number.
If compensation is
active the display will show +9305
and if it is inactive -9305.
Table 9305-3.
Curve Numbers
Thermocouple
Type
Chrome1 vs.
Au-0.07 at.% Fe
Chromel vs.
Au-0.03 at.% Fe
E
K
T
standard
Curve #
00
01
02
03
04
9305.7.3
Selection of Reference
Junction Compensation on the
DRc-93c
When a 9305 Thermocouple Input
Cards is installed, pressing the
SENSOR key will display either
+9305 or -9305.
The +9305 means
that the thermocouple voltage is
corrected for the Terminal Block
temperature. The -9305 means that
the thermocouple voltage is being
displayed with no compensation.
To select whether Reference
Junction Compensation is used or
not is accomplished from the front
panel by a combination of the
SENSOR key, SCAN
key and the
key and
key. The procedure
is as follows.
COPYRIGHT 6/88 LSCI
Model DRC-91C/93C
1.
2.
3.
4.
Press and hold the SENSOR key.
While holding the SENSOR key,
press the SCAN
key. You
may now release the SENSOR key.
To change the sign if in the
upper Display press the
key
while still holding down the
SCAN
key.
Similarly, to
change the sign if in the lower
Display press the
key while
still holding down the SCAN
key.
Release the
key (or
key)
and then the SCAN
key.
You should press the SENSOR key to
verify that the sign is as desired.
Selection of Reference
Compensation via the
Computer Interface
9305.7.4
Junction
To select or prevent Reference
Junction Compensation via the IEEE
interface, use the AC1C2 and BC1C2
comands described in the DRC-91C
(Section 4.8.5) or DRC-93C (Section
4.8.9) Instruction Manual.
The
Reference Junction Compensation bit
may be listed as Switch 3 or the
Thermal Correction bit (used on the
9318C card).
Turning on (1) that
position turns on the compensation.
9305.7.5
Adjustment
Rear
Panel
Offset
When
a
n e w o r different
thermocouple is attached to the
instrument it is desireable to
permit the addition of an offset to
compensate for discrepancies in the
thermocouple material, leads and
connections. An Offset Adjustment
trimpot is provided next to the
Terminal Block on the Back Panel to
allow quick calibration of the
thermocouple without removal of the
instrument cover.
COPYRIGHT 6/88 LSCI
9305 ThermocoupleInput C a r d
The procedure is as follows.
1.
Place the thermocouple in a
reference bath of known
temperature (liquid nitrogen,
Allow the system
ice, etc. )
to stabilize to the Reference
Temperature.
.
2.
With the front panel of the
instrument,
select the
thermocouple input and the
desired temperature units.
3a. On the DRC-91C enable Reference
Junction Compensation by
closing (1) switch 3 of the
appropriate SENSOR ID on the
rear of the instrument. Hold
the LOCAL key and verify the
display as +9305. See Section
9305.7.2
.
3b. On the DRC-93C enable Reference
Junction Compensation by using
and A,
the SENSOR, SCAN
or
keys. The Display should
show +9305 when the SENSOR key
is pressed.
See Section
9305.7.3.
4.
Adjust the Offset Adjustment
trimpot so that the Display
reads
the
Reference
Temperature.
Note :
The Offset Adjustment
compensates for the thermocouple
used in the calibration.
If
another thermocouple is attached,
or the thermocouple has aged, or
the configuration of the system is
changed, then the Offset Adjustment
must be repeated.
9305.7.6
Curve Data Format
The 9305 Thermocouple Input Card
will operate with a user defined
curve as well as the Internal
Curves listed in Table 9305-4.
Temperature is calculated by linear
interpolation between curve points.
9305-7
9305 Thermocouple Input Card
The card is hardware limited to
reading input between -15
millivolts and +15 millivolts. All
curves should be limited in
temperature so not to exceed these
voltage values.
If Reference
Junction Compensation is desired,
the thermocouple curve must be
normalized to zero degrees Celcius.
Compensation also limits the
practical range of the card by
approximately the room temperature
voltage of the thermocouple used.
The controllers are designed to
operate on sensor curve data in the
range of 0.00000 to 3.00000 volts
so thermocouple voltage must be
converted to this range before it
is entered into a curve table. To
obtain the proper table value from
a thermocouple voltage it must be
summed with 15 millivolts to make
it positive and multiplied by one
hundred to shift resolution.
vtable(v) = 100 *
(VTHERMocouple(mV) + 15 (mV))
A -15.0000 millivolt thermocouple
voltage will result in a 0.00000
volt table value and +15.0000
millivolts will result in 3.00000
volts.
Once the Thermocouple Curve has
been converted, carefully read and
follow the instructions in DRC-91C
Manual Section 4.14
or DRC-93C
Manual Section 4.16 on how to enter
the data into a controller.
9305.8
EQUIPMENT
CALIBRATION SCHEDULE AND
The design of the 9305 Thermocouple
Input C a r d is such that calibration
should not be required more often
than every six to twelve months in
order to keep the card within its
accuracy specification.
However,
if calibration is required, the
following equipment is needed:
9305-8
Model DRC-91C/93C
1.
2.
-
Digital Voltmeter (DVM) 5 1/2
digit resolution or better.
Precision Voltage Standardcapable of a 10 millivolt
signal to within ±1 microvolt.
The accuracy of the calibration
depends on the accuracy of the
Digital Voltmeter (DVM) and the
Voltage Standards used. Since very
often these values will not be
available to the user of this
instrument, Lake Shore Cryotronics,
Inc. offers a calibration service.
Contact a factory representative
for information concerning
calibration.
Setpoint calibration is
described in Chapter 5 of the DRC91C and DRC-93C Instruction manual.
The only additional instructions
required when calibrating the
setpoint D/A converter with the
9305 card is to make sure that the
Reference Junction Compensation is
turned off (Section 9305.7.3).
NOTE:
9305.9
CALIBRATION
The controller should be allowed a
one hour warm-up time to achieve
rated specifications.
Use the
following procedure to begin
calibration of
the 9305
Thermocouple Input Card.
1.
2.
3.
Remove the three top panel
screws and slide the panel off.
Configure the controller so the
card to be calibrated is the
CONTROL input.
Locate the DIP switch S1 on the
9305 Input Card. Open (0) S1.1
for calibration.
This forces
the 9305 to update Secondary
Sensor information every
conversion cycle. Under normal
operation (S1.1 closed (1))
COPYRIGHT 6/88 LSCI
Model DRc-91C/93C
4.
5.
6.
7.
Secondary sensor information is
updated once every 25 cycles.
Locate the
Secondary Sensor
current sensing resistor
terminals (I+ and I-), the
Secondary current source
adjustment (10µ) , the Control
Amplifier Span adjustment (CNT
V), and the A/D converter span
adjustment
(A/D)
on the
calibration cover for the 9305
Card.
Locate the Rear Panel Offset
Adjustment on the Terminal
Block.
Locate the test points TP24
(CNT V) and TPl (GND(2s)) of
the Calibration Card.
Avoid using clip on leads
during calibration because they
do not make good electrical
connections.
Attach test
equipment lead wires with the
terminal screws.
The calibration procedure
divided into three parts.
1.
2.
3.
is
Calibration of the Secondary
Sensor Current Source.
Calibration of the Control
Signal Amplifier and Rear Panel
Offset Adjustment.
Calibration of the Thermocouple
and Secondary Sensor A/D
converters on the 9305
Thermocouple card.
9305.9.1
secondary Sensor Current
Source calibration
1.
2.
Connect the DVM plus lead to
terminal I+ and the DVM minus
lead to the I- terminal.
Adjust the trimpot labelled
10µA so that the DVM reads
1.000 volt ±0.001 volt.
COPYRIGHT 6/88 LSCI
9305 Thermocouple Input Card
9305.9.2 Control Amplifier and Rear
Panel Offset Adjustment calibration
1.
With the front panel of the
i n s t r u m e n t , select the
thermocouple input and place in
the V (voltage) units.
2a. On t h e DRC-91C disable
Reference Junction Compensation
by opening (0) switch 3 of the
appropriate SENSOR ID on the
rear of the instrument.
See
Section 9305.7.2.
2b. On t h e DRC-93C disable
Reference Junction Compensation
by using the SENSOR, SCAN (t ,
and A, or
keys. The Display
should show -9305 when the
See
SENSOR key is pressed.
Section 9305.7.3.
3.
4.
5.
6.
7.
Connect the DVM plus and minus
leads to the TP24 (CNT V) and
TPl (GND(2s)) found on the
calibration card of the
controller.
Apply a zero signal to the +V
and -V Thermocouple Input
terminals by shorting across
the Terminal Block with a short
jumper wire.
Allow the
Terminal Block temperature to
settle for five minutes.
Adjust the Rear Panel Offset
Adjustment on the Terminal
Block until the output on the
DVM is 0.0000 volt. Be sure to
remove the jumper wire after
this step.
Apply a +10 millivolt signal to
the +V and -V Thermocouple
Input terminals on the Terminal
Block
and
allow
the
temperature to settle.
The DVM should read about -2
volts.
Adjust the input card
trimpot labeled CNT V (Control
9305-9
9305 Thermocouple Input card
M o d e l DRC-91C/93C
Voltage Span) until the output
on the DVM is -2.000 volts
±0.0001 volt.
9305.9.3 Thermocouple and Secondary
Sensor A/D Calibration
The Thermocouple and Secondary
Sensor A/D converters have an autozero function which means that the
only calibration required is for
the relative gain (span). The
procedure is as follows.
1.
2.
3.
4.
Make sure the instrument is
setup as described in parts 1.,
2a. (or 2b.) and 3. in the
previous section (Control
Amplifier Calibration).
Apply a +10 millivolt signal to
the +V and -V Thermocouple
Input terminals on the Terminal
Block.
The Display should read about
10 millivolts.
Adjust the
trimpot
labeled
A/D
(ThermocoupleA/D Span) so that
the voltage read on the Display
is 10.000 millivolts.
This test is to verify that the
A/D converter is symmetrical.
Apply a -10 millivolt signal to
the +V and -V Thermocouple
Input
terminals.
The DVM
should read +2.0000 ±0.0006
volt. The Display should read
-10.000 ±0.003. If it does not
meet these specifications, the
unit should be returned to the
factory for calibration.
9305.9.4
Reference Junction Test
This test is to verify that the
Reference Junction Compensation
circuitry is operating properly.
If this test does not produce the
following results please consult
the factory.
1.
Apply a zero volt signal to the
9305-10
+V and -V Thermocouple Input
terminals by shorting across
the Terminal Block with a short
jumper wire.
2.
3.
4.
Select the controller
display the 9305 card
temperature units.
Enable the Reference Junction
Compensation as described in
Section 9305.6. The reading on
the display should read Room
Temperature.
Disable the Reference Junction
Compensation and the display
should read Zero degrees
Celcius (the normalization
point of the curves).
9305.9.4
1.
2.
to
in
Calibration Completion
Close (1) S1.1 to return the
9305 to normal Secondary Sensor
update operation.
Remove anything that may be
shorting the two halves of the
terminal block.
3.
Verify that thermal correction
is properly selected.
4.
Slide the top cover onto the
instrument and replace the
three screws.
9305.10
OPTION COMPATIBILITY
The special nature of thermocouple
sensors and their connections
limits compatibility with Lake
Shore options and accessories.
Thermocouples must be attached
directly to a terminal block. The
8229 Scanner Input Option and 8085
External Sensor Scanner are not
adapted with terminal blocks so
they can not be used with the 9305
Thermocouple Card.
The 8225
Linerized Analog Output Option will
function in temperature units only
COPYRIGHT 6/88 LSCI
Model DRC-9lC/93C
w i t h a 9305 i n s t a l l e d , giving an
output of 10mV/K. The 8000 series
Precision Calibration options are
not available from Lake Shore f o r
thermocouple sensors.
9305.11
9305 Thermocouple Input Card
REPLACEABLE PARTS
Included in this section is Figure
showing the M o d e l 9305
Thermocouple Input C a r d Schematic,
R e p l a c e a b l e P a r t s L i s t and
i l l u s t r a t e d Component Layout. Also
included is Figure 9305-2 showing
the 9305 Terminal Block Schematic,
R e p l a c e a b l e P a r t s L i s t and
Component Layout.
9305-1
COPYRIGHT 6/88 LSCI
9305-11
9305 Thermocouple
Input C a r d
Table 9305-4.
Breakpoint
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
9305-12
9305
chromel vs.
0.0
3.5
8.0
13.5
18.0
24.0
30.0
52.0
60.0
65.0
70.0
80.0
90.0
105.0
115.0
125.0
135.0
145.0
160.0
170.0
180.0
195.0
210.0
225.0
240.0
265.0
275.0
285.0
305.0
325.0
999.9
VTC(mV)
-15.0000
4.6676
4.6067
4.5259
4.4571
4.3703
4.2869
3.9928
3.8830
3.8126
3.7411
3.5948
3.4436
3.2026
3.0374
2.8689
2.6957
2.5184
2.2468
2.0615
1.8725
1.5839
1.2905
0,9912
0.6847
0.1670
+ 0.0378
+ 0.2387
+ 0.6350
+ 1.0387
+15.0010
-
-
-
DRc-91C/93C
Thermocouple Curves
Au-0.03 at.%Fe
Temp(K)
Model
chromel vs.
Au-0.07 at.%Fe
Temp (K)
VTC (mV
0.0
1.4
3.0
4.8
7.0
10.5
19.0
26.0
48.0
58.0
70.0
80.0
90.0
100.0
110.0
120.0
135.0
150.0
165.0
180.0
200.0
220.0
245.0
270.0
300.0
305.0
310.0
315.0
320.0
325.0
999.9
-15.0000
5.2982
5.2815
5.2594
5.2285
5.1742
5.0315
4.9126
4.5494
4.3810
4.1733
3.9952
3.8132
3.6270
3.4370
3.2435
2.9477
2.6452
2.3372
2.0242
1.6004
1.1693
0.6232
0.0705
+ 0.5986
+ 0.7158
+ 0.8431
+ 0.9944
+ 1.1940
+ 1.4841
+15.0010
-
-
COPYRIGHT 6/88 LSCI
Model
DRc-91C/93C
9305 Thermocouple Input Card
Table 9305-4 (cont.).
Breakpoint
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
chromel vs.
Constantan
E
Temp(K) VTC(mV)
0.0
3.0
5.6
9.0
13.5
19.0
25.0
32.0
40.0
50.0
60.0
70.0
80.0
90.0
105.0
120.0
135.0
150.0
170.0
190.0
210.0
235.0
260.0
290.0
320.0
350.0
385.0
420.0
460.0
475.0
999.9
COPYRIGHT 6/88 LSCI
-15.0000
9.8355
9.8298
9.8182
9.7956
9.7570
9.7013
9.6204
9.5071
9.3366
9.1345
8.9030
8.6475
8.3673
7.9064
7.3943
6.8386
6.2400
5.3831
4.4564
3.4702
2.1605
0.7666
+ 0.9948
+ 2.8428
+ 4.7704
+ 7.1149
+ 9.5570
+12 4425
+13.5573
+15.0010
-
-
-
-
.
9305 Thermocouple Curves
chromel vs.
Alumel
K
Temp (K) VTC (mV)
0.0
3.0
6.0
10.0
14.5
19.5
25.0
32.0
40.0
48.0
58.0
65.0
75.0
85.0
95.0
105.0
120.0
135.0
150.0
165.0
185.0
205.0
230.0
260.0
295.0
350.0
395.0
460.0
510.0
575.0
999.9
.
-15 0000
6.4582
6.4551
6.4486
6.4376
6.4205
6.3951
6.3529
6.2913
6.2149
6.1022
6.0099
5.8634
5.6989
5.5156
5.3166
4.9881
4.6240
4.2267
3.7994
3.1866
2.5259
1.6463
0.5186
+ 0.8688
+ 3.1298
+ 4.9999
+ 7.6164
+ 9.6125
+12.2790
+15.0010
-
-
-
.
Copper vs
Constantan
T
Temp (K) VTC (mV)
0.0
3.0
6.5
11.0
16.5
22.0
29.0
38.0
48.0
60.0
75.0
90.0
105.0
120.0
135.0
155 0
175.0
195.0
220.0
245.0
270.0
300.0
330.0
360.0
395.0
430.0
470.0
510.0
555.0
575.0
999.9
.
-15.0000
6.2584
- 6.2523
6.2401
6.2184
6.1888
6.1404
6.0615
5.9535
5.7995
5.5753
5.3204
5.0337
4.7194
4.3767
3.8781
3.3278
2.7342
1.9295
1.0586
0.1254
+ 1.0616
+ 2.3247
+ 3.6639
+ 5.3095
+ 7.0419
+ 9.1113
+11.2758
+13.8053
+14.9685
+15.0010
-
9305-13
R E P L A C E M E N T P A R T S LIST
-
MODEL
LSCI P A R T N U M B E R
I TEM
NO
LSCI Part
Number
QtY
C3,4,14
15,24,
25
c9
C10-13,
23,32
C16,26
C19,27
101 - 1 3 2
101-027
2
2
CR 1
102-064
1
P2,P3
106-142
2
R1,16,
21,22
103-077
105-403
s1
u1
u2
u3
u4,5
U6
u7
U8
UP
U10,11
u12
U13
U14
U15
Y1
101 - 0 3 4
101-001
101-137
MFR
PART NO
MFR
6
CAP,PP,1.0MF,100V
FDYNE
MPP2X-1.0-100-10
1
6
CAP,POLY,.0015,100V
CAP,TANT,10MF,35V
CDE
SPRG
WMF1D15
119D106X0035DBl
C A P , .47MF, 100V
CAP,TANT,1.5MF,10V
FDYNE
SPRG
HPP-11.47MFD
150D155X9010A2
CONNECTOR, 6 P O S T LOCKING
RA H D R
MOL
2420-09-75-1061
4
TRIMPOT,2K
BOR
3299X-1-202
1
SWITCH ( 4 DIP PIANO)
GY H
76PSB04
DIODE,SWITCHING
102-041
104-345
104-511
104-660
104-5 2 8
102-040
IC, O P A M P
IC, O P AMP
IC, O P AMP
IC, A/D C O N V E R T E R
MOSFET, P CHANNEL
REGULATOR, -5V
REGULATOR, +5V
VOLTAGE REFERENCE,2.5V
IC, OPTOCOUPLER
IC, MICROPROCESSOR
IC, E P R O M ( P R O C R A M )
IC, 8 BIT L A T C H
V O L T A G E REFERENCE,l.ZZV
103-990
1
CRYSTAL,5.000M
102-010
INPUT C A R D
099
Description
1
1
1
2
1
1
1
1
2
1
1
1
1
104-081
104-005
104-001
104-465
104-074
104-020
9305
HZ
LT
NAT
PM I
TDYN
SIL
MOT
MOT
NAT
HP
I NT
1NT
NAT
MTRON
1N914
LTC1050CN8
LM308
OP07EP
TSC500CPE
3N163
7905
7805
LH336BZ-2.5
HCPL-273 1
P80C31
27C64-3
P82C82
LM313
MP1
5.000M
HZ
Figure 9305-1. Model 9305 Thermocouple
lnput
Card
REPLACEMENT
PARTS L I S T
-
MODEL 9 3 0 5
L S C I P A R T NUMBER
I TEM
NO
L S C I Part
Number
QtY
Description
C1,2
101 -022
2
CR1.2
CAP,PP,O.lMF,100V
102-064
2
P3
106-140
1
DIODE,SWITCHING
u1
1 0 4 - 081
1
INPUT
MODULE BOARD
113-180
MFR
FDYNE
MFR
PART N O
MPP11-0.1-100
1N914
CONNECTOR,6 POS SOCKET
MOL
IC, OP AMP
2139139-09-503061
LT
LTC1050CN8
Figure 9 3 0 5 - 3 .
Model
9 3 0 5 Thermocouple Input Card Module
Figure 9 3 0 5 - 2 . Model 9 3 0 5 Thermocouple Input Card
Model DRC-91C/93C
9317C/9318C Input Cards
9317C/9318C RESISTANCE I N P U T C A R D
9317C/9318C. 1 INTRODUCTION
This section contains information
pertaining to the Model 9317C/9318C
Resistance Input Card. Included is
a description, specifications,
installation, operation and
maintenance information.
9317C/9318C02 DESCRIPTION
The Model 9317C/9318C Resistance
Input Card is designed to be
installed in a DRC-91C/93C to
convert either Input A or Input B
(or both with two cards) to
accommodate sensors where the
voltage level must be kept at
levels on the order of 1 or 10
millivolts and where a thermal
voltage may exist. The 9317C/9318C
can be used with germanium, carbon
glass or carbon resistors or any
other negative temperature coefficient resistors.
Both cards read
in ohms from a full scale reading
of 10 ohms with 1 milliohm resolution to a full scale reading of
10,000 ohms with 0.1 ohm resolution
for the 9317C and 100,000 ohms with
1 ohm resolution for the 9318C. To
read temperature accurately, a
calibrated sensor and an 8000
Series precision Option is required.
Refer to Section
93 17C/9318C-5
for a detailed
description of the operation of the
9317C/93 18C.
9317C’9318C03
SPECIFICATIONS
Specifications for the Model
9317C/9318C Resistance Input Card
are given in Table 9317C/9318C-l of
this Section.
COPYRIGHT 12/87 ISCI
9317C/9318C.4
IN-ON
The 9317C/9318C can be installed in
a DRC-91C or a DRC-93C as either
Input A or Input B (or both with
two cards).
The 9317C/9318C is
installed prior to shipment if
ordered with either controller. If
only one 9317C/9318C is ordered and
its input is not specified when
ordered, it is installed in Input
A.
Use the following procedure for
the installation of the 9317C/9318C
Resistance Input Card. (Note: when
a card is ordered for field
installation, the Input Card
Configuration Table located on the
first page of the Instruction
Manual should be updated to keep
documentation current.
WARNING
To prevent shock hazard, turn off
the instrument and disconnect it
from AC line power and all test
equipment before removing cover.
1. Set the POWER switch to OFF and
disconnect the power cord from
the unit. Remove the three top
panel screws and slide the panel
off. Note from the calibration
cover the position of the Input
Card the 9317C/9318C will
occupy.
2. Remove
the four screws that
secure the calibration cover to
its clips and remove the cover.
3. If the 9317C/9318C is to replace
an existing Input Card, unplug
the Input Card which is to be
replaced. Disconnect the wiring
harness mating connector by
lifting the locking tab on the
Input Card and gently pulling
on the body of the wiring
harness mating connector.
9317C/93 18C-1
9317C/9318CInput cards
Model DRC-91C/93C
Table 9317C/9318C-1. Specifications, 9317C/9318C Resistance InputCards
Input Range:
9317C: less than 1 ohm to 10,000 ohms with a resolution of 1 part in
10,000 and an accuracy of 0.1% of reading for resistances from 1 to
1,000 ohms and 0.5% of range for resistances from 1,000 to 10,000 ohms
9318C: less than 1 ohm to 100,000 ohms with a resolution of 1 part
in 10,000 and an accuracy of 0.05% of reading for resistances from
10 to 10,000 ohms and 0.25% of range for resistances less than 10
ohms and from 10,000 to 100,000 ohms.
Sensor Excitation: Current range is from 0.1 microampere to 1
milliampere. The current is varied automatically to maintain the
voltage across the sensor at 1 millivolt for the 9317C and 10 millivolts for the 9318C. Current polarity is periodically reversed to
allow for automatic digital correction for thermal EMFs in the sensor
connections and leads.
Temperature Range: Depends on sensor type used. Sensor resistance
scales from 1 to 10,000 ohms (9317C) or 100,000 ohms (9318C) can be
accommodated.
Sensors (Ordered Separately): Card optimized for CGR Series Carbon
Glass or GR Series Germanium Resistance Thermometers. Other negative
temperature coefficient resistors (such as thermistors) can also be
used.
Sensor Response Curve: The DRC-91C/93C display resistance in ohms
directly. A calibrated sensor and an 8001 Precision option curve
generated using Lake Shore's proprietary Polynomial Interpolation
Algorithm are required for the unit to display temperature accurately.
Input Resistance: Greater than
109
ohms (sensor voltage measurement).
Maximum Sensor Power Dissipation: Depends on sensor .resistance.
Voltage applied is 1 millivolt for the 9317C (power is 1/R in microwatts) or 10 millivolts for the 9318C (power is 100/R in microwatts).
Display Resolution: 5 digits. Displays 0.000 to 9999.9 ohms for the
9317C and 0.000 to 99999. ohms for the 9318C. Resultant temperature
accuracy is a function of sensor characteristic and is the product of
the input accuracy (in percent) times R (dT/dR) plus any transfer
inaccuracy introduced by the sensor response curve.
Temperature Control Signal: Card generates an analog voltage output
signal which is related to the sensor temperature. The instrument
generates a similarly related set point voltage based on the set point
resistance or temperature selected. Real-time analog comparison of
these two voltages provides the required control signal.
93 17C/93 18C-2
COPYRIGHT 12/87 LSCI
Model DRc-91C/93C
4. Connect
the wiring harness
mating
connector to the
9317C/9318C Input Card making
sure that the wiring harness
locking tab is seated over the
extended edge of the wiring
harness mating connector. Plug
the 9317C/9318C into the Input
C a r d Slot with the component
side facing to the left of the
unit as viewed from the front.
Make sure the card is thoroughly
seated. Verify that the wiring
harness is in place correctly by
noting that the “A” or “B” on
the harness connector is facing
up (if it is not, review the
harness installation again).
5. Install the calibration cover by
reversing step 2.
6. Install the top panel.
9317C/9318C. 5 OPERATION
The 9317C/9318C is a highly
complex, microprocessor controlled
Input Card.
It's resistance
measuring technique is distinctly
different from the way a DMM would
measure resistance.
Most DMMs
force a large enough signal across
the device being measured to make
any thermal offset negligible.
using this method in a cryogenic
environment could add a significant
amount of power, in the form of
sensor self heating, to the test
system. The 9317C/9318C Input Card
limits the amount of power added to
the system by limiting the voltage
across the sensor to 1 (9317C) or
10 millivolts
(9318C).
The
9317C/9318C can also reverse the
current polarity in order to
correct for thermal EMFs in the
sensor connections and leads.
The 9317C/9318C current source has
four ranges: 0.1 to 1 microamperes
(Range 1), 1 to 10 microamperes
(Range 2), 10 to 100 microamperes
(Range 3) and 100 to 1000 microamp-
COPYRIGHT 12/87 LSCI
9317C/9318C Input Cards
eres (Range 4). Each range has 64
independent current values.
The
ranges overlap each other (for
example, Range 1
Value 60 is
equivalent to Range 2
Value 6) so
that a smooth transition from range
to range can be made. The current
value, as well as direction, is
controlled by a 16 bit bipolar D/A
converter. This current resolution
is required to maintain as close to
1.05
(9317C) or 10.5
(9318C)
millivolts across the sensor as
possible. The on-card microprocessor stores calibration constants
for each of the four ranges at the
end point values of 6 and 60 for
both the positive and negative
directions (a total of 16 current
calibration constants in all).
-
-
The resulting sensor voltage is
converted from a differential to
single ended signal and amplified
by a factor of 1000 (9317C) or 100
(9318C). The amplified signal is
digitized by a microprocessor
controlled 15 bit A/D converter.
The microprocessor also has
calibration constants stored for
the gain and offset of the input
amplifier. As a result of the A/D
resolution and calibration constant
manipulation of the sensor signal,
the sensor signal can be digitized
with a resolution of 1 part in
10,000 over most of the resistance
range the 9217C/9318C covers.
There is also a sample-and-hold
network on the card so that when
the sensor signal is reversed for
thermal correction while controlling, the correct polarity of the
control signal is maintained.
9317C/9318C.5.1
Thermal Correction
Selection for the DRC-91C
The control thermal correction
function is enabled or disabled
using switch 3 of the appropriate
SENSOR ID located on the rear panel
of the DRC-91C.
9317C/93 18C-3
9317C/9318C Input Cards
When switch 3 of the SENSOR ID is
CLOSED (ON) the thermal correction
is enabled. When switch 3 is OPEN
(OFF) the thermal correction is
disabled.
Pressing the LOCAL key
for the appropriate channel will
display either ±18 C or ±17 C. The
plus (+) that the control thermal
correction is enabled. The minus
(-)
means the Control thermal
correction is disabled.
9317C/9318C.5.2
Thermal Correction
Selection for the DRC-93C
When a 9317C or 9318C Resistance
Input Card is installed, pressing
the SENSOR key will display either
±9317C or ±9318C for the appro_
priate channel. The plus (+) means
the control thermal correction is
enabled. The minus (-) means the
control thermal correction is
disabled.
Enable or disable the control
thermal correction from the front
panel by using a combination of the
,
and
keys
SENSOR, SCAN
as follows:
1. Press and hold
key.
the SENSOR
2. While holding the SENSOR key,
press the SCAN
key.
The SENSOR key may be
released.
3. To change the sign
(change
the enabled/disabled status)
of the upper display press
the
key.
Similarly, to
change the sign of the lower
display press the
key.
4. Release the
then the SCAN
5
or
key.
key,
Press the SENSOR key to
verify that the proper sign
is selected.
9317C/9318C-4
Model DRC-91C/93C
9317C/9318C.5.3 Operation as the
Sample Input
the input occupied by the
9317C/9318C is selected as the
Sample Input (Sample only -not
Control), the 9317C/9318C determines the sample resistance by
forcing the voltage across the
sensor to 1.05 (9317C) or 10.5
(9318C) millivolts as quickly as
possible with the microprocessor
controlled current source.
Once
the forward current range and value
results in the desired voltage, the
current is reversed and the thermal
value determined. As long as the
voltage across the sensor does not
change more than 0.5% of reading
from one reading to the next, the
forward and reverse readings are
taken each t h e the input card is
asked for an update (approximately
once a second) and a new thermal
value is determined.
If the
voltage changes more than 0.5% of
reading, the card stops reversing
the current and uses the thermal
value previously determined until
the sensor signal stabilizes.
When
9317C/9318C.5.4
Control Input
Operation as the
When the input occupied by the
9317C/9318C is selected as the
Control Input (Control only, or
Sample and Control) the operation
of the card changes.
Since the
card has to provide a signal across
the sensor that will control the
heater power as well as measure
resistance (or temperature), it can
no longer force the sensor signal
to 1.05
or 10.5 millivolts
immediately.
When a set point is entered by the
user, the DRC-91C/93C calculates
its equivalent control sensor
resistance.
From this resistance
and the calibration constants
(current and voltage) for the
9317C/9318C input card, the set
COPYRIGHT 12/87 LSCI
Model DRC-91C/93C
point voltage which will result in
a sensor voltage as close to 1.05
or 10.5 millivolts as possible
(when the control point is reached)
is calculated.
If the thermal
correction is active and there has
been a valid thermal value determined, it is included in the
calculation.
If no valid thermal
has been determined, or the thermal
correction is inactive, a thermal
value of 0 is used. The resultant
voltage is then sent to the main
board of the controller as the set
point voltage (or equivalent
“resistance”) for control.
The 9317C/9318C input card then
determines if the control sensor
resistance is above or below the
equivalent set point “resistance”.
If the actual resistance is less
than the set point “resistance”, an
over-temperature condition exists
and the heater power should be off.
The 9317C/9318C changes the current
it applies to the sensor in order
to maintain between 0.8 and 1.0
(9317C) or 8 and 10 (9318C)
millivolts across it until the set
point current range and value have
been reached.
In this way, the
heater remains off until the actual
sensor resistance approaches the
set point “resistance”. Once the
final control sensor current value
has been reached, the 9317C/9318C
allows the sensor voltage to range
as high as 1.3
(9317C) or 13
(9318C) millivolts. If the sensor
voltage
(and the equivalent
resistance) continues to increase
(an under-temperature condition
exists), the 9317C/9318C then
reduces the current to maintain
between 1.1 and 1.3 (9317C) or 11
and 13 (9318C) millivolts across
the sensor.
The heater power
remains on.
Even though this
operation takes the sensor voltage
away from the optimum signal until
it reaches the control point, the
resulting error in the resistance
determination is small. If the new
COPYRIGHT 12/87 ISCI
9317C/9318C Input Cards
set point results in an undertemperature condition, the opposite
operation is performed.
If the thermal correction is
active, the 91C/93C monitors the
sensor resistance until it is
within 0.5% of the set point
resistance.
Once it is, the
91C/93C signals the 9317C/9318c
card to reverse the sensor current
and update the thermal value. The
9317C/9318C card and the 91C/93C
use this new thermal to determine
the resistance and correct the set
point.
The thermal value is
updated every 120 instrument update
cycles (about 2 minutes) after the
initial update. When the set point
is changed, the previous thermal
value is used until the correction
criteria is met and the thermal
updated again.
9317C/9318C.6 CALIBRATION SCHEDULE
AND EQUIPMENT
The design of the 9317C/9318C
Resistance Input Card is such that
re-calibration should not be
required more often than every six
to twelve months in order to keep
the card within its accuracy
specification.
However, if recalibration is required, the
following equipment is needed to
re-calibrate the card:
1. Digital Voltmeter (DVM)
-
digit resolution or better.
2. Five
5 1/2
Precision Standard
Resistors which are accurate in
value to at least 0.01%. Their
values in ohms must be:
(5)
9317C: 1, 10, 100, 1K, 1 0 K
9318C: 10, 100, 1K, 1 0 K , 100K
3. Precision
Voltage Standardcapable of a plus and minus 10
millivolt signal to within ±0.1
microvolt.
9317C/93 18C-5
9317C/9318C Input cards
Since very often these values will
not be available to the user of
this instrument, Lake Shore
Cryotronics, Inc. offers a recalibration service.
Contact a
factory representative for information concerning re-calibration.
Note that the card believes that
the correct resistance and voltage
is applied during calibration,
therefore the accuracy of the
calibration depends on the accuracy
of the standards used.
9317C/9318C.7
CALIBRATION
The 91C/93C should be allowed a one
hour warm-up time to achieve rated
specifications.
References are
made in the calibration procedure
to eight calibration switches, CAL
8 through CAL 1.
Refer to Table
9317C/9318C-2 for the hardware
switch definitions of CAL 8 through
CAL 1. References are made to test
points, adjustments and calibration
switches that are labeled on the
calibration cover.
Use the
following procedure to calibrate
the 9317C/9318C Resistance Input
Card.
1.
2.
3.
Remove the three top panel
screws and slide the panel off.
Configure the input that
contains the 9317C/9318C as the
SAMPLE input only and make the
units
Turn off Digital
Filtering and Thermal Correction (DIP switches of the
appropriate SENSOR ID switches
2 and 3 to the OPEN (OFF)
position for the DRC-91C or
disable fram the front panel on
the DRC-93C).
-
Current Source Zero
Connect
the 10K (9317C) ohm precision
resistor across the +I and -I
pins of the Resistance Input
Card input connector and enable
both CAL 8 and CAL 7 of the
9317C/93 18C-6
Model DRC-91C/93C
card.
Attach the plus and
minus leads of the DVM to the
test points marked V+ and
V-respectively
of
the
9317C/9318C FCB and adjust the
trimpot marked IZ so that the
voltage reads as close to zero
as possible.
If this voltage
is not close to zero, it may
effect the sensor
current
setting.
Consequently, this
operation should be performed
before any current calibrations
are performed. Disable CAL 7
and continue. Note that CAL 8
will remain enabled for all
calibration operations.
-
4a. Voltage Match or Span Connect
the DVM plus and minus leads to
the V+ and V-Sensor Output
Signal. terminals of the
MONITORS connector for the
input being calibrated. Apply
a +1 (9317C) or +10 (9318C)
millivolt signal to the +V and
-V Sensor Input
terminals.
Enable CAL 6 on the card (CAL 8
is still enabled).
The DVM
should read about 1 volt and
the display of the unit should
read approximately
10000.
Adjust the trimpot labeled A/D
so that the voltage read on the
DVM matches the display of the
unit (if the DVM reads 1.0085
make the display read 10085.).
If the trimpot is adjusted wait
a minimum of 10 readings before
disabling CAL 6.
4b. Apply a -1 (9317C) or -10
(9318C) millivolt signal to the
input and enable CAL 5. Do not
adjust any of the trimpots.
Disable CAL 5 after approximately 30 seconds.
When the
display goes to
0. the unit
has completed determining the
voltage input calibration
constants and has stored them
in the 9317C/9318C calibration
EEPROM.
COPYRIGHT 12/87 LSCI
Model DRC-91C/93C
5.
6.
7.
8.
9.
Current Range 1, V a l u e 6Configure the 10K (9317C) or
100K (9318C) resistor to
simulate the sensor.
Enable
CAL 4 and monitor the unit's
display.
The display should
indicate the number 106, for
approximately 30 seconds and
then display 0. indicating the
end of the calibration.
Disable CAL 4 and Continue.
Current Range 1, V a l u e 60 and
Current Range 2, V a l u e 6Substitute a 1K (9317C) or 10K
(9318C) resistor for the
previous resistor and re-enable
CAL 4.
The display will
display the number 160. for
approximately 30 seconds, then
the number 206. for another 30
seconds and when complete, a 0,
will be displayed. Disable CAL
4 and continue.
Current Range 2, V a l u e 60 and
Current Range 3, V a l u e 6Substitute a 100 ohm (9317C) or
1K (9318CO resistor for the
previous resistor and enable
CAL 3.
The display will
indicate 260. for approximately
30 seconds, then
306. for
another 30 seconds and finally
a
0,
Disable CAL 3 and
continue.
Current Range 3, V a l u e 60 and
Current Range 4, V a l u e 6Substitute a 10 ohm (9317C) or
100 ohm (9318C) resistor for
the previous resistor and
enable CAL 2. The display will
indicate 360. then 406. with
each t h e period being approximately 30 seconds. When
the 0. appears, disable CAL 2
and continue.
Range 4, V a l u e 60Finally substitute the 1 ohm
(9317C) or 10 ohm (9318C)
resistor for the previous
resistor and enable the last
Current
COPYRIGHT 12/87 LSCI
9317C/9318C Input Cards
switch, CAL 1.
The display
will indicate 460. for approximately 30 seconds and then
a
0. indicating that the
calibration of the card is
complete.
Disable CAL 1 and
then CAL 8.
Calibration - A
special set point calibration
is required for a DRC-91C or
DRC-93C with two 9317C/9318C
Input Cards
or if the
9317C/9318C is the only Input
card.
Since the set point
voltage is related to the set
point resistance, and is
determined with the individual
card calibration constants,
there is no way to enter a set
point that results in a predetermined value for the set
point. The Internal ID Switch
(S7 on the Main Board) is used
in the calibration. Note the
position of the Internal ID
switches before proceeding.
Attach the plus and minus leads
of the DVM to TP25(SP V) and
TP1(GND(2s) )
respectively of
the Calibration and Service
Card.
Make switch 7 CLOSED
(ON). This forces the unit to
output a set point of 0 volts.
Adjust the
SP ZERO ADJ
trimpot until the DVM reads as
close to zero as possible.
Turn ON switch 6 of the
Internal ID. This forces the
unit to output a set point of2.7 volts. Adjust the SP SPAN
ADJ trimpot until the DVM reads
as close to -2.7000 volts as
possible.
This procedure
should be done until the 0 and
-2.7 readings are as close as
possible to the calibration
values.
Before returning to
normal operation, make sure
switches 7 and 6 of the
Internal ID are OPEN (OFF)
10. Set Point D/A
.
11. Replace the calibration cover
and then the top cover.
93 17C/ 93 18C-7
9317C/9318C Input cards
Table 9317C/9318C-2.
Switch Definitions
Calibration
Viewed from the Component Side of
9317C/93 18C
9317C/9318C. 8
Model. DRC-91C/93C
INFORMATION
SENSOR
CURVE
The curves used with the
9317C/9318C Input Card are generated using a proprietary Polynomial
Interpolation Algorithm developed
by Lake Shore. The format for the
data to be stored using the XCN1N2
comand (as outlined in Section 4)
is the same as for a standard curve
except the resistance is converted
to a LOG value (where 1000 ohms
would look like 4.0000). Refer to
APPENDIX B for a definition of the
curve requirements. The curve data
is in resistance order.
The
resistance and temperatures for the
9317C/9318C are in ohms up to
100,000 ohms and in kelvin up to
399.9
9317C/9318C. 9 REPLACEABLE PARTS
Viewed through Calibration Cover
Switch CAL
S1A-4
S1A-3
8
7
Definition (switch closed)
9317C
SlA-2
S1A-1
S1B-4
S1B-3
S1B-2
S1B-1
9317C/9318C-8
6
5
4
3
2
1
Included in this section is Figure
9317C/93 18C-1.
It includes the
Model 9317C/9318C Resistance Input
Schematic, replaceable parts list
and illustrated component layout.
Refer to the manual for ordering
information.
Calibration Enable
Current Source DAC Zero
+1mV
-1mV
1K-10K
100 ohm
10 ohm
1 ohm
9318C
+10mV
-10mv
10fv10OK
1K ohm
100 ohm
10 ohm
Input A/D Cal
Input A/D Verify
current Verify
current Verify
Current Verify
Current Verify
COPYRIGHT 12/87 LSCI
Figure 9317C-1. Model 9317C Resistance Input Card
REPLACEABLE PARTS LIST
ITEM
NO
c1
C2,3
c11
LSCI P a r t
Number
101- 137
101-067
101-025
QtY
1
2
1
CAP,TANT,10MF.35V
CAP,CER,30PF,500V
CAP,PP,.33MF,100V
105-405
2
CAL
u1
104-509
104-652
104-001
106-345
104-419
1 0 4 - 060
1
1
2
IC ,E E P R O M
I C , O P AMP
U3,8
u4,5
U6
u7
U9,10
u11
9317C R E S I S T A N C E S E N S O R I N P U T
D e s c r i p t i o n
S1A,B
u2
-
2
1
1
2
ENABLE (4
DIP
HFR
RA)
IC,MICROPROCESSOR
IC,OPTOCOUPLER
IC,D/A
CONVERTER
IC,ANALOG SWITCH
IC,SWITCHED CAPACITOR
IC,A/D
CONVERTER
I C , O P AHP
HFR PART
119D106X0035DB1
CD15ED300J03
MPP-11 .33MFD
GYH
76PSB04
OK1
X I COR
PM I
N80C51VS
HP
BB
NAT
LT
TDYN
MAX
X2404
OP07EP
HCP L 273 1
DAC703BH-5
LF13202
LTC1043
TSC500CPE
MAX430CPA
-
1
3
104-098
104-020
104-660
1
1
1
I C , B l N A R Y COUNTER
REGULATOR,-5V
CD4020BCN
IC,EPROM
NAT
MOT
INT
Y l
103-990
1
CRYSTAL,5.000MHZ
MTRON
MP1
P2
106-142
1
CONNECTOR,
16
U14
U15
U17
6 P O S T R A HDR
NO
CD E
CD E
FDYWE
104-078
104-465
1 0 4 - 089
u12,13
CARD
LSCI
79L.05
27C64-3
5.000MHZ
Figure 9318C-1.
Model 93186 Resistance Input Card
REPLACEABLE PARTS LIST
IT E M
NO
LSCI P a r t
Number
QtY
-
9 3 1 8 C R E S I S T A N C E SENSOR I N P U T C A R D
Description
MFR
MFR P A R T NO
C l
C2,3
c11
101-137
101-067
101-025
1
2
1
CAP,TANT,10MF.35V
CAP,CER,30PF,500V
CAP,PP,.33MF,100V
CDE
CDE
FDYNE
119D106X0035DB1
CD15ED300J03
M P P - 11 . 3 3 M F D
S1A,B
105-405
2
CAL ENABLE (4 D I P RA)
GYH
76PSB04
u1
u2
104-509
104-652
104- 001
1
1
2
OK I
3
IC,MICROPROCESSOR
I C , EEPROM
I C , O P AMP
IC,OPTOCOUPLER
IC,D/A
CONVERTER
IC,ANALOG SWITCH
IC,SWITCHED CAPACITOR
IC,A/D
CONVERTER
IC,OP AMP
MAX
M80C51VS
X2404
OP07EP
HCPL -2731
DAC703BH-5
LF13202
LTC1043
TSC500CPE
MAX430CPA
1 0 4 - 098
104 020
1 0 4 660
--
1
1
1
I C , B I N A R Y COUNTER
REGULATOR,-5V
I C , EPROM
NAT
MOT
IN T
CD4020BCN
79L05
27C64-3
Y1
103-990
1
CRYSTAL,5.000WHZ
MTRON
MP1 5.000MHZ
P2
106- 142
1
CONNECTOR,
U3,8
u4,5
U6
u7
U9,10
u11
U12,13
16
U14
U15
U17
104-345
104-419
1 0 4 060
-
104-078
104-465
104-089
2
1
1
2
1
6 P O S T R A HDR
X I COR
PM I
HP
BB
NAT
LT
TDYN
LSCI
Model DRC-91C/93C
Model 8223 Rs-232C Interface
MODEL 8223 RS-232C
8223.1 INTRODUCTION
This Section contains information
pertaining to the Model 8223
RS-232C Interface for the DRC91C/93C Temperature Controller.
Included is a description,
specifications, installation,
operation
and
maintenance
information.
number of 1 bits in the character.
Refer to Table 8223-1 for parity
determination.
Table 8223-1. Parity Determination
Number of "1”s Parity
Parity
in character Specified Bit
Odd
Even
Odd
Even
8223.2 DESCRIPTION
The 8223 RS-232C Interface is
designed to be installed in a DRC91C/93C and provide an interface
with an external Rs-232C instrument
such as a computer, modem or CRT.
The interface operates in a half
duplex mode (it can only transmit
and receive information in one
direction at a time) and data
transmission is asynchronous (each
character is bracketed by start and
stop bits that separate and
synchronize the transmission and
receipt of data). The baud rate is
switch selectable at 300 or 1200
baud and the interface maintains
EIA voltage levels for data
transmission.
Figure 8223-2 gives a transmission
format which shows the data bits
framed by the start and stop
synchronization bits. The data is
transmitted using two voltage
levels which represent the two
binary states of the digit. A logic
0 (or SPACE) is +3 to +12 VDC. A
logic 1 (or MARK) is -3 to -5 VDC.
When data is not being transmitted,
the line is held low (MARK state).
When the transmission device is
ready to send data, it takes the
line to the high (SPACE) state for
the time of one bit.
This
transition is called the start bit.
The remaining data is then
transmitted.
If a parity bit is
used, it follows the character.
The parity bit is determined by the
COPYRIGHT 12/87 ISCI
INTERFACE
Odd
Odd
Even
Even
0
1
1
0
The Model 8223 RS-232C Interface
has a 25 pin D style connector
located on the rear panel.
Pin
Assignments are shown in Table
8223-2.
Table 8223-2. Connector Pin
Assignments for RS-232C
Pin
1
2
3
4
5
6
7
8
20
Description
Protective Ground
Transmitted Data
Received Data
Request to Send
Clear to Send
Data Set Ready
Signal Ground
Rcvd Ln Sgnl Dtctr
Data Terminal Rdy
Signal
AA
BA
BB
CA
CB
cc
AB
CF
CD
The Rs-232C signals are used in the
following manner:
-
Protective Ground (AA)
conductor
is taken to case ground potential
and is common with the signal
ground (AB)
.
-
Transmitted Data (BA)
transmits
data using the EIA voltage levels
(+12V and -5V).
-
Received Data (BB)
accepts data
using EIA voltage levels.
8223-1
M o d e l 8223 Rs-232C I n t e r f a c e
Figure 8223-2.
-
R e q u e s t t o Send (CA)
indicates t o
the host computer or terminal that
the DRC-91C/93C I n t e r f a c e is ready
t o transmit data.
The Interface
transmits data on l i n e BA when the
''ON" state is maintained on CC, CB
and CF, while a l o w level on these
l i n e s inhibits transmission by the
Interface.
C l e a r t o Send (CB)
-
indicates t o
Interface
that
data
transmission
is
allowed.
Internally pulled up t o maintain
"ON” s t a t e when l e f t disconnected.
the
-
Data Set Ready (CC)
indicates t o
Interface t h a t t h e h o s t
computer o r terminal is not i n a
test m o d e and that power is ON.
the
M o d e l DRC-9 1C/9 3C
,
Word Structure
8223.3
Switches
8223.3.1
S t o p B i t (s)
Configuration
of
Dip
Selection of Baud Rate
Model 8223 has a f i e l d
selectable baud rate using D I P
switch package S1 (8 switches) on
the I n t e r f a c e card. The baud rate
is selected by closing the switch
position for the desired baud rate
and making sure a l l o t h e r p o s i t i o n s
are open.
T a b l e 8223-3 gives the
baud rate s e l e c t i o n table.
Only
the 300 and 1200 baud rates have
b e e n t e s t e d and a r e f u l l y
supported.
The
Table 8223-3. Baud Rate Switch S1
Signal Ground (AB) - this l i n e is
the common s i g n a l connection for
the Interface.
Received Line Signal Detector (CF)
this l i n e is held p o s i t i v e (”ON”)
when the I n t e r f a c e is receiving
signals from the host computer.
When held l o w (”OFF”) the BB line
i s clamped t o i n h i b i t d a t a
reception. I n t e r n a l l y pulled up t o
maintain “ON” s t a t e when l e f t
disconnected.
-
-
Data Terminal Ready (CD) asserted
by the I n t e r f a c e whenever the DRC91C/93C/8223 p o w e r is “ON” t o
indicate that the I n t e r f a c e is
ready t o receive and t r a n s m i t data.
8223-2
8223.3.2
word structure Selection
The word s t r u c t u r e is determined by
s w i t c h s e t t i n g s f o r character
length, p a r i t y and s t o p b i t s using
D I P switch package S2 on the
I n t e r f a c e Card ( 6 switches). R e f e r
t o T a b l e 8223-4 f o r s e t t i n g s where
“0” is OPEN and “1” is CLOSED.
COPYRIGHT 12/87 LSCI
M o d e l DRC-9 1C/ 93C
Table
8223-4.
switch s2
M o d e l 8223 Rs-232C Interface
Word
Structure
Table 8223-5. Model 8223 Rs-232C
Interface specifications
- Asynchronous
Transmission M o d e - H a l f Duplex
Baud Rate - 300 o r 1200 B i t s / s e c
T h i n g Format
(Factory set t o 300)
-
B i t s per Character
7(excluding
start, s t o p o r p a r i t y b i t s )
-
P a r i t y Enable
Enabled/Disabled
(Factory set Enabled)
-
P a r i t y Select Odd or Even
(Factory set Odd)
N u m b e r of Stop B i t s - 1 o r 2
(Factory set t o 1)
- Transmit
o r receive using E I A voltage
levels (+12V and -5)
D a t a I n t e r f a c e Levels
Note :
For the not supported
settings,
the interface w i l l
respond, but the card has not been
tested w i t h these s e t t i n g s a t the
factory. X is a don't care s e t t i n g
for that s w i t c h .
8223.4 SPECIFICATIONS
Specifications f o r the M o d e l 8223
are given i n
RS-232C I n t e r f a c e
T a b l e 8223-5.
8223.5 INSTALLATION
The 8223 Rs-232C I n t e r f a c e is
factory installed i f ordered w i t h a
DRC-91C Temperature Controller o r
can be f i e l d installed a t a later
date.
If f i e l d i n s t a l l a t i o n is
required,
u s e t h e following
procedure.
1. Configure the 8223 baud rate and
w o r d s t r u c t u r e switches as outlined
in Section 8223-3.
COPYRIGHT 12/87 ISCI
WARNING
To prevent shock hazard, turn
off the instrument, disconnect
it from AC line power and a l l
test equipment before removing
cover.
2. Set the POWER s w i t c h t o OFF and
disconnect t h e p o w e r cord from the
unit.
Remove the three t o p panel
screws and slide the panel o f f .
N o t e on the c a l i b r a t i o n cover the
p o s i t i o n of Option S l o t 2 which the
8223 w i l l occupy.
3. Remove the f o u r screws that
secure the c a l i b r a t i o n cover t o its
c l i p s and remove the cover. Remove
the two back panel mounting c l i p s
that secure the J10 blank cover
p l a t e t o the i n t e r f a c e opening and
remove the p l a t e .
8223-3
M o d e l 8223 Rs-232C I n t e r f a c e
4. Remove the red jumper JMP6 on
the Microprocessor Board. This is
the jumper c l o s e s t t o the f r o n t
edge of the microprocessor card.
Plug the i n t e r n a l i n t e r f a c e
cable i n t o the 8223 printed c i r c u i t
board (PCB) w i t h the locking tab
configured properly. Plug the 8223
PCB into Option S l o t 2 w i t h the
component side t o the left of the
u n i t as viewed from the f r o n t .
Gently thread the RS-232C i n t e r n a l
cable along the inside edge of the
rear panel so t h a t it w i l l n o t
i n t e r f e r e with the i n s t a l l a t i o n of
the c a l i b r a t i o n cover or t o p cover.
5.
Position the 25 p i n Rs-232C
Interface connector in the J10
opening on the back panel and
secure it in place using the s c r e w s
provided,
6.
7. I n s t a l l the c a l i b r a t i o n cover by
reversing procedure 3.
8. Install the top panel.
8223.6 OPERATION
The 8223 RS-232C I n t e r f a c e has a
256 character FIFO b u f f e r for input
commands.
The i n t e r f a c e accepts
commands,
the same as for the
Interface, u n t i l it sees
the End-of -Line
(EOL)
sequence.
The 8 2 2 3 requires a carriage
r e t u r n / l i n e feed (CR) (LF) or j u s t
l i n e feed (LF) as its input EOL and
transmits carriage r e t u r n / l i n e feed
( C R ) (LF)
as its o u t p u t EOL.
Following the EOL Sequence the
command string is processed.
IEEE-488
operation of t h e I n t e r f a c e l i n k is
i n i t i a t e d by the computer.
The
computer w i l l t r a n s m i t either a
Program C o d e o r an Output Request
t o the 8223 Interface.
The DRC91C/93C w i l l respond t o the Output
R e q u e s t with t h e a p p r o p r i a t e
response o r w i t h the response and
an error message ( i f an error was
8223-4
M o d e l DRC-91C/93C
detected). The i n t e r f a c e responds
t o Program C o d e Commands by s t o r i n g
the variables input.
The Programming C o d e s
T a b l e s 4-4, 4-7 and 4-8
given i n
are input
only and do not r e s u l t i n a
response from the i n t e r f a c e .
The
C o d e s TN1 and Z N 1 w i l l be accepted
and updated even though they have
no relevance t o the i n t e r f a c e (the
EOL terminator sequence is always
(CF) (LF)
and there is no EOI
status).
The MN1 command can be
considered the "OFF LINE” (Local)
and “ON LINE" (Remote or Remote
w i t h Local Lockout) states. When
"OFF LINE” (Local) parameters such
as SENSOR I D (as w e l l as Gain, R a t e
and R e s e t ) a r e updated from the
hardware s e t t i n g s while “ON LINE"
these parameters can be updated
from the computer only.
The Output Statement commands given
i n T a b l e s 4-9 and 4-10 w i l l r e s u l t
i n t h e requested data being output
immediately following the reception
of the EOL sequence. I f more than
one Output Statement command is
given, the l a s t one received w i l l
be acknowledged. Programming C o d e s
and Output Statements can be s e n t
i n the same command s t r i n g .
For
example, the command s t r i n g :
S24.5P4012OD25R2
would r e s u l t i n the.Set Point being
updated t o 24.5, t h e Gain t o 40,
the R e s e t t o 20, the R a t e t o 2 5 and
the Heater Range t o 10-3.
No
Output Statement w a s given so no
response w i l l be output by the
interface, The command s t r i n g :
S24.5P40120D25R2WO
w i l l r e s u l t i n the WO contents
being output by the i n t e r f a c e .
( R e f e r t o Section 4 f o r a d e t a i l e d
discussion of the Output Statement
commands,)
COPYRIGHT 12/87 L S C I
M o d e l DRC-91C/93C
M o d e l 8223 RS-232C Interface
4-11
and 4-12 give the
Program Curve Summary.
The XDT,
XDA and XDN1N2 commands are Output
Statement s t y l e commands which
r e s u l t i n a response from the
interface.
The balance of the
commands are Programing Code s t y l e
commands which do not r e s u l t in a
response from the i n t e r f a c e . C a r e
must be taken w i t h the XCN1N2
command not t o overrun the 256
c h a r a c t e r b u f f e r of the 8223
interface.
As
i n t h e IEEE
operation, i f a hardware problem is
detected in modifying one of the
memory locations, an ERR01 e r r o r
w i l l be displayed i n the Display
and instrument operation w i l l be
halted.
Consult a factory
representative i f t h i s error
occurs.
Tables
There are three errors that could
be detected by the 8223 i n t e r f a c e
a s d e f i n e d i n Table 8223-6.
Detection of an error does not
e f f e c t t h e o p e r a t i o n of
the
interface.
The software t h a t
i n t e r p r e t s the data tries t o match
the character input t o the possible
command i n p u t s and processes the
command.
T h e e r r o r is a l s o
transmitted by the i n t e r f a c e the
next time it is asked f o r a
response, The error is transmitted
i n addition t o the Output Statement
data output.
For example, i f a
framing e r r o r w e r e detected i n a
command s t r i n g transmitted t o a
DRC-91C/93C as :
P5OW3
the interface might respond w i t h :
Err12
50.,25.,20.,2,047(CR)
(LF)
I f the error w e r e detected in the
transmission of the “P”, the gain
change would be ignored; i f it was
i n the "50”, one or two numerics
may have been generated.
I f the
e r r o r w e r e detected i n t h e “W”, the
interface may not respond, i n which
COPYRIGHT 12/87 LSCI
case it would need t o see another
Output Statement command. I f the
error was in the “3”, the i n t e r f a c e
may o r may not have responded w i t h
W 3 data, it may d e f a u l t t o wo.
Although e r r o r s r a r e l y occur, it is
suggested that any commands s e n t t o
the 91C/93C be echoed back by
s e n d i n g t h e appropriate Output
Statement command and inputting the
stored parameters. Any e r r o r t h a t
is detected is cleared following
the first transmission after the
error,
Table 8223-6. Interface Error Codes
Number
Error/Possible Cause
Err10
P a r i t y Error
may be
caused by s i g n a l l i n e
transients o r i n c o r r e c t l y
specified p a r i t y .
Err11
Overrun Error
caused
by the main processor
not reading the input
character before the next
one becomes available.
The overrun character (s)
are l o s t .
Err12
Err13
-
-
-
Framing E r r o r
may be
caused by s i g n a l l i n e
t r a n s i e n t s or i n c o r r e c t l y
specified s t o p b i t s o r
or character length.
-
Input Buffer Overrun
caused by more than 256
characters being input
input t o t h e FIFO buffer.
Any characters received
after the 256th character
are l o s t .
8223.7 INTERFACING EXAMPLES
HP-86B Computer, H a l f
Duplex Without Handshake.
Example 1.
8223-5
Model 8223 RS-232C Interface
The HP82939A S e r i a l I n t e r f a c e f o r
the HP-86B is p r e s e t a t the factory
f o r t h e following d e f a u l t values:
1. Interface select code = 10
2. Baud rate = 300 Baud
3. Autohandshake = O f f
4. Character Length = 7 b i t s
5. P a r i t y = Odd
6. Stop b i t s = 1
7. Cable Option = Standard (25 pin
socket)
Since t h e HP d e f a u l t Baud rate,
character length, p a r i t y and stop
b i t configuration are t h e same as
those of t h e 8223 I n t e r f a c e when
shipped, none of t h e switches on
t h e 8223 board need t o be changed.
When connecting the HP-86B S e r i a l
I n t e r f a c e t o t h e 8223 Interface, a
t r a n s i t i o n cable needs t o be made
t o connect t h e socket connector of
the HP t o the socket connector of
the 8223 I n t e r f a c e .
Figure 8223-3
Model DRC-91C/93C
output it t o t h e 8223. The program
w i l l t h e n input t h e s p e c i f i e d
8223's response, d i s p l a y it and
return for another command.
10 REM HALF DUPLEX w/o HANDSHAKE
15 REM I/O TEST (RS232 TEST1)
20 DIM A$[256],B$[3000]
25 REM A$ IS OUTPUT B$ IS INPUT
30 INPUT A$ ! MAKE SURE TO GIVE AN
35 ! OUTPUT STATEMENT COMMAND
40 OUTPUT 10 ; A$ ! OUTPUT COMMAND
50 ENTER 1 0 ; B$ ! INPUT THE DATA
55
! FROM THE CONTROLLER
60 DISP B$ ! DISPLAY DATA
7 0 GOTO 30 ! RETURN FOR MORE
80 END
Example 2.
HP-86B Computer, Half
Duplex, w i t h Handshake.
Figure
8223-4
shows
the
adapter
f o r H a l f Duplex w i t h
handshake communications with an
cable
HP-8 6 B
Serial
Interface.
arrows i n d i c a t e the source
direction of signal flow.
Figure 8223-4.
Handshake
The
and
Half Duplex, with
Connector to HP-86B
shows t h e adapter cable that must
be made.
The arrows i n d i c a t e t h e
source and d i r e c t i o n of signal
flow.
Figure 8223-3.
Handshake
Half Duplex W/O
Connection t o HP-86B
The following program w i l l input a
command from t h e keyboard and
8223-6
Computer
DRC-9 1C/ 9 3C
COPYRIGHT 12/87 LSCI
M o d e l DRC-91C/93C
M o d e l 8223 Rs-232C Interface
The Auto Handshake c a p a b i l i t y of
the HP-86B Serial I n t e r f a c e m u s t be
enabled,
The addition of the
program line:
1 6 CONTROL
DSR, DCD,CTS
10,2;7
!
Figure 8223-6.
General Serial
Interface Interconnecti
'on for Half
Duplex without Handshake
ENABLE
t o the program above enables the HP
t o receive and transmit i n a
handshake mode.
Example 3.
General
I n t e r f a c e Interconnection.
Serial
HP-86B
Serial Interface
S t a n d a r d cable c o n f i g u r a t i o n
already takes care of some of the
i n t e r f a c e interconnection problems
t o route s i g n a l s t o their proper
pins.
Figures 8223-5 and 8223-6
give more general interconnection
configurations for H a l f Duplex w i t h
and without Handshake.
The
8223-5.
General Serial
Interface Interconnection for Half
Duplex with Handshake
Figure
COPYRIGHT 12/87 LSCI
*Note:
I t may be necessary t o
jumper p i n s 5, 6, 8 and 20 t o
disable the handshake functions of
t h e Host. This is n o t required f o r
the 8223 Interface.
8223.8 REPLACEABLE PARTS
Included in this s e c t i o n is Figure
8223-1,
It includes t h e M o d e l 8223
RS-232C I n t e r f a c e Option Schematic,
r e p l a c e a b l e p a r t s l i s t and
i l l u s t r a t e d component l a y o u t .
R e f e r t o the manual f o r ordering
information.
8223-7
Figure 8223- 1. Model 8223 RS-232C Interface Option
REPLACEABLE P A R T S LIST
ITEM
NO
LSCl Part
Number
QtY
-
MODEL
8223 RS-232C I N T E R F A C E OPTION
D e s c r i p t i o n
MFR
MFR
P A R T NO
J1
106-253
1
25 P I N D S T Y L E P L U G
Q1
102-071
1
XSTR,
s1
S2
105-408
105-406
1
1
D I P S W I T C H 8 POS
D I P S W I T C H 6 POS
GYH
GYH
76608
76SB06
U1
UZ
104-053
1
1
1
1
1
1
1
IC, B A U D G E N E R A T O R
REGULATOR, +12
I C , 6 B I T MUX
IC, Q U A D 2 I N P U T N O R
IC, UART
IC, T R A N S C E I V E R
IC, TRANSCEIVER
MOT
MC14411
INT
DM81LS95AN
74LS02
P8251A
MC1488L
MC1489NL
u4
102-018
104-310
104-203
U6
104-720
u3
us
u7
104-523
104-721
TRW
DB-25s
2N5225
GEN PURP N P N
MOT
MAT
MOT
MOT
78L12
M o d e l DRC-91C/93c
M o d e l 8225 Analog Output
MODEL 8 2 2 5 A N A L O G O U T P U T
8225.1 INTRODUCTION
This section contains information
pertaining t o the M o d e l 8225 Analog
O u t p u t f o r t h e DRC-91C/93C
Temperature Controller.
Included
is a description, specifications,
installation, operation and maintenance information.
Model 8225 Analog
O u t p u t specifications
Table 8225-1.
8225.2 DESCRIPTION
The 8225 Analog Output is designed
t o be installed i n a DRC-91C/93C
and provide an analog output
proportional
t o t h e Kelvin
temperature of the display o r
control sensor f o r the purpose of
recording, either w i t h a s t r i p
chart recorder o r other similar
device, the sensor temperature.
The analog output is present on the
J 3 MONITORS
connector on the
91C/93C back panel w i t h pin C being
the V+ output and pin D being the
v- output.
8225.3 SPECIFICATIONS
Specifications for the M o d e l 8225
Analog Output a r e given i n T a b l e
8225-1.
8225.4 INSTALLATION
The 8225 can be installed in the
DRC-91C/93C Option S l o t 1 or Option
S l o t 2 ( i f a Model 8223 RS-232C
Interface is not present).
The
8 2 2 5 Analog Output is factory
installed i f ordered w i t h a DRC91C/93C o r can be f i e l d i n s t a l l e d
a t a l a t e r date.
If field
installation is required use t h e
following procedure.
1. Configure the red jumper on the
8225 printed c i r c u i t board f o r
SAMPLE (Display Sensor) o r
CONTROL (Control Sensor).
COPYRIGHT 12/87 LSCI
Note a:
The resistance of the
9317C and 9318C Input Cards is not
output by the 8225 because of the
number of orders of magnitude t h e
display can cover.
The analog
output of temperature displayed by
these Input cards is available i f a
precision Option is present f o r the
sensor.
8225-1
M o d e l 8225 Analog Output
M o d e l DRC-91C/93C
If re-calibration is needed, use t o
t h e following procedure.
The
following equipment is used t o
calibrate the 8225 Analog Output:
1
2. Set the power switch t o OFF and
disconnect the p o w e r cord from
the unit. Remove the three top
panel screws and slide the panel
off.
Note on the calibration
cover the position of Option
Slot 1 o r 2 w h i c h the 8225 w i l l
occupy
the four screws that
secure the calibration cover t o
its c l i p s and remove the cover.
3, Remove
4. Plug the 8225 printed c i r c u i t
board i n t o option S l o t 1 o r 2
w i t h the component side t o the
l e f t of the u n i t a s viewed from
the front. Thread the two black
and white w i r e s from the 8225
along the inside edge of the
rear panel and solder the white
w i r e t o MONITOR connector J3-
Pin
5.
C
Precision Voltage Source w i t h an
output resolution of 100 uV out
of 3 V o r better.
The u n i t should be allowed one hour
t o warm up t o achieve rated
specifications.
U s e the following
procedure t o c a l i b r a t e the 8225
Analog output:
1. Remove
the three top panel
s c r e w s and slide the panel off.
2. Connect the DVM plus lead t o the
J3 MONITORS connector pin C and
the m i n u s lead t o pin D.
3. W i t h the load r e s i s t o r s , o r the
voltage standard, t o simulate
the input sensor go t o a low
temperature and a d j u s t t h e
trimpot labeled Z ( f o r Zero) on
the calibration cover u n t i l the
voltmeter
reading corresponds
t o 10 mV/K.
G o t o a high
temperature and a d j u s t t h e
trimpot labeled S ( f o r Span)
6. I n s t a l l the top panel.
o u t p u t r e s o l u t i o n and
equivalence is given i n Table
8225-1.
For a temperature display
of 100.00 K the 8225 would output
1.000 V.
The output is rounded t o
the equivalent u n i t f o r the 1 mV
output. A display of 23.42 K would
r e s u l t i n an output of 0.234 V and
a display of 23.47 K would result
i n an output of 0.235 V.
8225.6 CALIBRATION
The M o d e l 8225 has been calibrated
t o specification p r i o r t o shipment.
8225-2
Voltmeter/Mult i m e t e r
d i g i t resolution o r
4½
2. Precision Standard Resistor t o
simulate the input sensor or a
Install the calibration cover by
reversing procedure i n 3.
The
(DVM)
better.
and black w i r e t o Pin D.
8225.5 OPERATION
-
Digital
4. R e p e a t procedure in paragraph 3
u n t i l there is no further Zero
o r Span adjustment required.
5.
Install the top panel.
8225-7 REPLACEABLE PARTS
Included in this Section is Figure
8225-1. It includes the M o d e l 8225
Analog
Output
schematic,
r e p l a c e a b l e p a r t s l i s t and
i l l u s t r a t e d component l a y o u t .
R e f e r t o the manual f o r ordering
information.
COPYRIGHT 12/87 LSCI
Figure 8225-1. Model 8225 Analog Output Option
REPLACEABLE PARTS L I S T
ITEM
NO
U1
U2
u3
Part
LSCI
Number
104-524
104-425
104 001
-
QtY
1
1
1
-
MODEL 8 2 2 5 ANALOG OUTPUT OPTION
Description i o n
IC, P O R T EXPANDER
l C , 4 DIGIT DAC
IC, O P A M P
MFR
IN T
BB
PM I
MFR P A R T N O
P8255A-5
D A C 7 1 -CCD-V
OP07EP
Model DRC-91C/93c
8229 Scanner Conversion Option
8229 SCANNER CONVERSION OPTION
8229.1 INTRODUCTION
This Section contains information
pertaining to the Model 8229
Scanner Conversion for the DRC91C/ 93C Temperature Controller
Included is a description,
specifications, installation,
o p e r a t i o n and maintenance
information.
Table
8229-1.
J9
8229
Scanner
Conversion option connections
.
8229.2 DESCRIPTION
The 8229 Scanner Conversion is
designed to be installed in a DRC91C/93C
and provides four
additional channels of sensor input
to Input A.
The 8229 inputs are
designated Al through A4 and their
selection is identified in the
display window at the left of the
display. With the 8229 installed,
the DRC-91CJ93C is expanded from
the standard dual sensor input to
handle six input sensors.
The 8229 A 1 through A4 channels can
be selected directly (using the
SENSOR A key) or included in the
SCAN sequence.
A n independent
Dwell time (0 to 99 seconds) can be
assigned to each of the additional
inputs.
The Al through A4 channels of the
Model 8229 Scanner are accessed
through a 24 pin "D” style
connector located in the J9 Option
Port on the 91C/93C rear panel.
Pin assignments for the connector
are shown in Table 8229-1.
The pin configuration for this
connector is identical to the pin
configuration for the IEEE-488
connector.
Even though the Input A contacts
are not on the J9 connector, the
sensor signal from Input A is
routed through the 8229 Scanner.
COPYRIGIT 12/87 LSCI
In essence, the 8229 routs the
sensor signals from all five Input
A channels to the A Input Card.
The A 1 through A4 8229 inputs are
designed for four lead measurements
and have independent pairs of
current and voltage leads.
The
current
leads
have
a
make-before-break switching action
and the voltage
leads are
break-before-make.
The BO through
B2 outputs on J9 are a BCD
representation of the channel
selected with BO being the least
significant bit and B2 the most
significant bit (a 0 represents
logic LO and a 1 logic HI w i t h
respect to the Digital Ground on
J9). Logic 000 represents channel
AO, 001 channel A l , 010 channel A2,
011 channel A3 and 100 represents
channel A4 on B2, B1 and BO
respectively.
8229.3 SPECIFICATIONS
Specifications for the Model 8229
Scanner Conversion option are given
in Table 8229-2.
8229-1
8229 Scanner Conversion Option
Table 8229-2.
Model 8229 Scanner
Conversion specifications
Number of channels: 4 (in addition
to the existing Inputs, A and B ) ,
designated Al through A4.
Contact Configuration:
4 pole (2
current poles make-before-break,
2 voltage poles break-before-make).
Maximum Input Voltage:
or peak AC.
Maximum current:
10
32 volts DC
milliamperes.
Thermal O f f s e t : Less than 3 microvolts per contact on break-beforemake poles, less than 50 microvolts
on others.
Contact Resistance:
Less than 1
open channel Isolation: >1010 ohms
Input/Output:
24 pin “D” style
connector, mate supplied.
Channel Selection: Front panel
SENSOR A key increments AO, A l , A2,
A3, A4, AO, etc. each t h e it is
pressed or automatically in the
SCAN mode. All front panel
operations can be duplicated over
the remote interfaces.
switch Contact Life:>10 6 operations
at rated load.
Configuration: Channels A0 through
A4 are configured as Remote
Position A00 through A04 with
respect to Sensor. Curve
selection with 8229 present.
Channel Selected Data:Chnnl selected
present in BCD form on J9 connector.
8229.4 INSTALLATION
The 8229 Scanner Conversion is
factory installed if ordered with
an DRC-91C Temperature Controller
8229-2
Model DRC-91C/93C
or can be field installed at a
later date. If field installation
is required, use the following
procedure.
WARNING
To prevent shock hazard, turn off
instrumentanddisconnectitfrom
line power and all test equipment before removing cover.
AC
1. Set the POWER switch to OFT and
disconnect the power cord from
the unit. Remove the three top
panel screws and slide the panel
off.
Note on the calibration
cover the position of option
Slot 2 which the 8229 will
occupy
2. Remove the four screws that
secure the calibration cover to
its clips and remove the cover.
Remove the two back panel
mounting clips that secure the
J9 blank cover plate to the
interface
opening and remove
the plate.
3. Plug the internal
sensor lead
cable into the 8229 printed
circuit board (FCB) with the
locking tab configured properly.
Plug the 8229 PCB into Option
Slot 2 with the component side
to the left, of the unit as
viewed from the front. Thread
the 8229 internal cable along
the inside edge of the rear
panel so that it won't interfere
with the installation of the
calibration cover or top cover.
4. Position the 24 pin 8229 Scanner
connector in the J9 opening on
the back panel and secure it in
place using the screws provided.
5. Disconnect the Input C a r d wiring
harness from the A Input
lifting the locking tab
Input Card connector and
on the body of the
Card by
on the
pulling
wiring
COPYRIGHT 12/87 LSCI
Model DRC-91C/93C
harness mating connector. Plug
the Input C a r d wiring harness
i n t o the 8229 input making sure
that the w i r i n g harness locking
t a b is seated properly,
Thread
the 8229 output cable along the
camponent side of the 8229 and
plug the cable i n t o the Input
Card making sure t h e locking tab
is seated properly,
6.
Install the c a l i b r a t i o n cover by
reversing procedure 2 .
7 , Install the t o p cover panel.
8229.5 OPERATION
Operation of the 8229 Scanner
Conversion can be implemented
either l o c a l l y , from the f r o n t
panel, or remotely through the
remote interfaces.
8229.5.1 Local 8229 Operation
The 8229 A 1 through A4 channels are
accessed l o c a l l y using the SENSOR A
key.
The Display Sensor is
incremented each t i m e the SENSOR A
key is pressed i n the sequence A,
A l , A2, A3, A4, A etc.
8229.5.1.1 Channel Dwell Times
The dwell t i m e s for the Al through
channels are selected the same
as for A and B. See Sections 3.8.3
and 3.8.4
f o r a complete
description of this operation.
A4
8229
Scanner Conversion Option
channels. See Section 3 . 8 . 6 f o r a
d i s c u s s i o n of
how t o s e t
resolution.
8229.5.2 Remote 8229 Operation
The remote operation of the 8229
Scanner is covered i n Section 4,
REMOTE OPERATION.
See T a b l e 4-7
and Section 4 . 1 1 e n t i t l e d THE
OPTIONAL SCANNER CARD.
8229.5.3 Curve Selection
The 8229 is considered an i n t e r n a l
Remote Position. The A0 through A4
channels are i n t e r p r e t e d as Remote
Position A00 through A04 for curve
s e l e c t i o n when the SENSOR A I D
Switch 4 is OPEN ( 0 ) .
The curve
for the input is then determined
from T a b l e 3-4 (the Curve N u m b e r t o
Position N u m b e r Correlation T a b l e ) .
A complete discussion
of curve
s e l e c t i o n is given i n Section 3 . 9
and in p a r t i c u l a r Section 3.9.2.1.
8229.6 REPLACEABLE PARTS
Included in this Section is Figure
It includes the M o d e l 8229
Scanner Conversion option
schematic, replaceable parts list
and i l l u s t r a t e d component layout.
R e f e r t o the manual f o r ordering
infomation.
8229-1,
.
8229 5.1.2 Units
The units for the Al through A4
channels are the same as f o r Input
and are defined by the A Input
Card.
Selection of units is
covered in Section 3.8.5.
A
. .
8229 5.1 3 Resolution
Resolution is by input card and not
channel.
Consequently, r e s o l u t i o n
is t h e same f o r a l l scanner
COPYRIGHT 12/87 LSCI
8229-3
Figure 8229-1.
Model 8229 Scanner Conversion Option
REPLACEABLE P A R T S L t S T
I TEU
NO
LSCI
Part
Number
-
MODEL 8229 SCANNER CONVERSION OPTION
Description
QtY
MFR
M F R P A R T NO
K1-5
K6-10
105-321
105-322
5
5
RELAY,DPST,DRY REED
RELAY,DPST,DRYREED
COTO
COTO
CR-3402-05-
MP 1
104-250
1
CONNECTOR
AML
57-30240
P2
P3
106-142
106-424
1
1
6 POST L O C K I N G RA HDR
26 P I N R A HEADER
MOLX
TBA
2420-09075-1061
609-2602MR.
Ul
U2,3
104-524
104-210
1
2
IC, P O R T E X P A N D E R
INT
P823 5 A -5
7406
IC,
OC HEX
KIT
INVERTER
CR-7102-05-1010
Lake Shore Cryotronics, Inc.
APPLICATION NOTES
This appendix includes the following Lake Shore documentation:
1. Fundamentals For Usage Of Cryogenic Temperature Controllers – Application Note .....................Page 1
2. Standard Curve 10 – Technical Data ................................................................................................Page 8
3. DT-470 Series Temperature Sensors Installation and Operation – Application Note.....................Page 10
4. Measurement System Induced Errors In Diode Thermometry – Article Reprint.............................Page 14
FUNDAMENTALS FOR USAGE OF CRYOGENIC TEMPERATURE CONTROLLERS
by
Dr. John M. Swartz • Lake Shore Cryotronics
575 McCorkle Blvd. • Westerville, OH 43082
Lawrence G. Rubin • MIT National Magnet Laboratory
170 Albany St. • Cambridge, MA 02139
I INTRODUCTION
Cryogenic temperature controllers have been available for years, but users often have an incomplete understanding of
their operating principles and of the closed-loop interactions between the controller and the controlled low temperature
environment. The object of this primer is to address this problem by presenting some fundamental and practical concepts
of control at low temperatures. The so-called "three-mode" or "PID" controller, utilizing Proportional (gain), Integral
(reset), and Derivative (rate) functions, will be discussed and examples given of its operation and adjustment. While the
emphasis will be placed on analog control systems, the advantages and disadvantages of digital versus analog control
will also be presented.
II CHARACTERISTICS OF CRYOGENIC TEMPERATURE CONTROL SYSTEMS
The adjective "cryogenic" as applied to temperature control systems defines a set of conditions that distinguishes such
systems from those for which the great majority of applications exist, i.e., industrial processes in which temperatures are
above—and often well above—room temperature. There are at least five factors which crucially affect temperature
control performance when one compares a cryogenic system with that existing inside a furnace, for example:
1. The values of heat capacity (lower, Cp, and thermal conductivity (often higher, κ, are such that much shorter thermal
time constants (τ α Cp/κ) are the rule at low temperatures.
2. The temperature sensor used in a furnace is almost always one of a variety of thermocouples with sensitivities in the
10-100uV/°C range. In the cryogenic regime, resistance thermometers (both metallic and semi-conductive), diode,
and capacitance thermometers provide from one to three order-of-magnitude higher sensitivity.
3. The heat input for furnaces is almost always derived from a line frequency source, and is controlled by relays,
variable transformers, saturable reactors, or SCRs. Experiments performed in a cryostat usually involve low level
signals, and hence require a low noise background. For that reason, ripple-free direct current, usually controlled by a
series transistor bank, should be used to power the heater.
4. As one traverses the cryogenic regime from the liquid helium range up towards room temperature, there can be quite
large variations in both the thermal time constants and thermometer sensitivities.
5. In the case of the furnace in which the load does not experience large endo- or exothermic reactions, the heat input
required to maintain a set point temperature is approximately constant. This is because the heat loss through a fixed
thermal conductance to the room temperature environment outside the furnace is also constant. However, there are
cryogenic systems where the low temperature environment provided by, e.g., a surrounding cryogen such as a liquid
helium or liquid nitrogen bath, may vary drastically as the level of the cryogen changes. In addition, the thermal
conductance to the outside world is highly dependent on the gas pressure (vacuum) maintained in the cryostat. The
resulting variations in "cooling power" will cause the heat input requirements to be anything but constant. A few
cryogenic systems employ a controller cooling loop, but this type of system will not be discussed.
Most of the difficulties in cryogenic control applications are associated with factors 4 and 5, where changes in parameters
are involved.
Application Notes
1
Lake Shore Cryotronics, Inc.
III PROPORTIONAL CONTROL
The block diagram in Figure 1 shows a systems in which
only proportional control is being used. In this system,
the desired control temperature setting (set point) is
being compared to the sensor signal and the difference,
or error signal (including polarity), is amplified within the
controller. When the sensor temperature corresponds to
the set point temperature (in voltage for a diode or
resistance for a resistor), the sensor signal will be equal
to, but opposite in polarity to the set point signal and the
error signal will be zero. In older instruments, the set
point is normally calibrated in millivolts or volts or
resistance, corresponding to the sensor output signal.
Most modern controllers have stored within them the
appropriate voltage-temperature or resistancetemperature sensor characteristic so that the set point
can be calibrated directly in temperature. However, as
discussed in Section VII, this convenience feature can
compromise the resolution and accuracy of the
controller.
The output of the controller is dc power to a resistive
heater, the output magnitude of which depends on the
size and sign of the error signal, as well as on the gain
of the deviation amplifier and the output power supply.
Since the controller's power output state tracks the
deviation amplifier output, it is evident that the power
output is proportional to the magnitude of the error
signal. In process control nomenclature, this response is
described in terms of "proportional control".
Let us examine the behavior of the sensor signal—set
point—deviation circuit in a modern cryogenic
controller, the Lake Shore Cryotronics Model DRC-82C.
In figure 2, the amplifier output (deviation gain times
error) is plotted against the error signal for two amplifier
gains: Av = 100 and Av = 1000. "Gain" in this closed
loop system refers not to the power gain, as in an audio
amplifier, but is related to the maximum amount of error
signal allowed before the controller is directed to
produce full output power. The DRC-82C requires a 0 to
8 volt signal from the deviation amplifier to drive the
power output stage from zero-to-maximum. In Figure 2,
For Av = 1000, there is a narrow band of error signals
(0 to -8 mV) within which the proportional action occurs.
This "proportional band" expands tenfold for Av = 100,
and so on for lower gains; obviously, gain and
proportional band are inversely related. Proportional
band is expressed as a percentage of full scale range.
FIGURE 1. Block diagram of Cryogenic Temperature Controller. Av is
amplifier voltage gain.
FIGURE 2. Output plot of the deviation amplifier showing Proportional
Bands for gain settings of 100 and 1000. For the DRC-82C, the
maximum available gain is 1000.
FIGURE 3. Output Power versus error signal in voltage or equivalent
temperature of sensor for two different power settings: (A) corresponds
to a sensor sensitivity of -50 mV/K; (B) corresponds to a sensor
sensitivity of -2.5 mV/K. Note that the curves are linear in voltage, not
power.
Note that the proportional band in mV can be converted
to temperature in kelvins if the sensitivity of the sensor
in mV/K is known. As an example, suppose the sensor
producing the error signal in Figure 2 had a sensitivity of 1 mV/K and the set point full scale range was 100 mV = 100 K.
The proportional band would then be 8% (or 8 K) and 80% (or 80 K) for Av = 1000 and 100, respectively. In cryogenic
applications, this terminology is less significant; gain, which is multiplicative, is usually more useful, since it is more easily
understood by the user.
The power output stage of a cryogenic controller may or may not have variable gain associated with it. If the controller
has several output power stage ranged for example, 5, covering 5 orders of magnitude in power) as does the DRC-82C,
then the controller output into a 50 ohm load and with a gain of 200 for 5 watts and 50 watts would have the response
shown in figure 3. Note that the overall voltage and power gain of the controller is modified by changing the output power
settings.
2
Application Notes
Lake Shore Cryotronics, Inc.
To illustrate the effect of the sensor, in more detail, consider
the idealized curve (Figure 4) for a Lake Shore silicon diode
which has a nominal sensitivity of -50 mV/K below 30 kelvin
and -2.5 mV/K above 30 kelvin. Figure 3 illustrates the effect
of converting the voltage error signal (horizontal axis) to its
equivalent temperature error for the two sensitivity regions of
the silicon diode sensor. These curves introduce the
concept of loop gain dP/dT (watts/kelvin), which includes the
gain of the sensor as well as that of the deviation amplifier
and power output stage. As the transition in temperature
from above 30 kelvin to below 30 kelvin is made, the loop
gain is increased by a factor of 20 because of the increased
sensitivity of the silicon diode thermometer. Because of
noise and thermal phase lag, the deviation amplifier gain will
normally have to be reduced by the same factor so that the
loop gain remains relatively constant.
In order to maintain any desired temperature above that of
FIGURE 4. Idealized curve for Lake Shore Cryotronics, Inc. DTthe cryogen in a cryogenic system, of course some level of
500 Series silicon diode temperature sensors.
heater power must be supplied by the controller. We have
seen in Figures 2 and 3 that a non-zero temperature error signal is
necessary to produce an output, and that the magnitude of the
error—or temperature offset— is a function of the power output
level and the loop gain. Let us demonstrate the nature of the offset,
also called droop, with an example.
Assume that a system sample block (the mass whose temperature
is to be controlled) has a finite heat capacity, but that its thermal
conductivity is infinite, as is the thermal conductance between the
block and the sensor and heater. The result will be that the
temperature within the block will be isothermal, no matter at what
rate the block is heated or cooled. For the following discussion,
ignore any noise associated with the system and assume that to
control at 20 kelvin, the heating power required is 0.2 watts.
Assume also that 50 watts of heater power is available, reducible in
five steps of one decade each. Figure 5 shows the control offset for
an amplifier gain of 100 and three output power settings which will
deliver enough power to the system to balance the cooling power.
FIGURE 5. Effect of output power setting on offset for a
The temperature offsets for a power level of 0.2 watts at 20 kelvin
proportional controller only.
are easily calculated from Figures 2 and 4 for the three maximum
power settings: 0.1 K for a 50 watt setting, 0.32 for a 5 watt setting, and 1.0 for the 0.5 watt setting. As expected, the
temperature offsets become smaller as the loop gain increases. However, there are limits to this approach as we move
from the idealized example to a real system.
The Real World
Unfortunately, the thermal conductivity within a system is not infinite, and both it and the heat capacity may vary by
several orders of magnitude between 1 K and 300 K. Also, the controller, the sensor, the sensor leads, and the block
may all have electrical noise. This noise is amplified by the controller; for a high enough amplifier gain setting, the output
of the controller will become unstable and oscillate. In addition, the placement of the sensor with respect to the heater
and the sensor construction and mounting itself introduce thermal lags. This is due to the finite thermal conductivity of the
block and the thermal resistances between the heater, sensor and the block. These thermal lags introduce a phase shift
between the controller output and the sensor, which will reduce even further the gain at which the system will be stable.
Therefore, the thermal block design is extremely important in the proper performance of any cryogenic system. No
controller can make up for poor thermal design of the system, nor can good design overcome the inherent limiting
properties of the materials and sensor packages which are currently available.
Application Notes
3
Lake Shore Cryotronics, Inc.
Since the thermal conductivity of cryogenic materials is finite, good practice dictates that the controller power output be
the same order of magnitude as the cooling power. If, for example, the cooling power is 0.2 watt, and 50 watts is
available, a change in set point to a higher temperature outside the proportional band of the controller will dump 50 watts
into the system block. Due to the thermal lag of the block, etc., a large temperature overshoot may occur, with the system
stabilizing only after several oscillations. This thermal lag can easily be observed since the sensor temperature will
continue to rise long after the output from the controller has been reduced to zero. The obvious way to reduce this effect
is to limit the heater power to the system to, for example, 0.5 watts. This can readily be done with a controller such as the
DRC-82C which has multiple maximum output power settings. The overshoot will therefore be smaller when the set point
is changed and the system will stabilize much faster although the rate of temperature rise will be less. Because changing
the power output setting affects the loop gain (dP/dT), it may be necessary to readjust the deviation amplifier gain
(controller gain setting) for optimum control. It is normally good practice to determine the power requirements for one's
system prior to or during the first experimental run. Some system manufacturers may have that information available and
may possibly supply a power load curve with the system.
Two other aspects of temperature control should be mentioned. First, ON-Off controllers are frequently encountered at
room temperature and above. As the name implies, such systems have only two states: power on when the temperature
is below the set point, and off when it is above. The proportional controller with excessive loop gain approximates this
mode. Although ON-OFF controllers perform adequately with large furnaces, for example, they are generally
unsatisfactory for cryogenic applications, because of the relatively short thermal time constants encountered at low
temperatures.
Secondly, some controllers, such as the DRC-82C, have a manually adjustable power output control. This control can be
used in either of two modes: (1) open loop, with a manual adjust of heater power in place of the signal from the deviation
amplifier and (2) automatic, where the adjustment is in addition to the controller's closed loop signal. Mode 1 is extremely
helpful in set up procedures and in subsequently determining the power levels associated with the desired temperatures.
In Mode 2, one can reduce and sometimes eliminate temperature offset by providing the required power without the need
for a large error signal to drive the output stage. This latter method has a name—manual reset—and serves as an
introduction to the next section on reset control.
IV PROPORTIONAL (GAIN) PLUS INTEGRAL (RESET) TEMPERATURE CONTROL
The manual reset adjustment described above varies markedly with the temperature set point and with the often
changing heater power demands of the system. Thus, it is normally neither convenient nor desirable to have to resort to
such a means of eliminating temperature droop (offset). Instead, suppose a circuit could be added to the loop that would:
(1) sense that there is a steady state offset signal within the proportional band; (2) make a bit-by-bit addition to the power
output, proportional to the magnitude of the offset; and (3) continue the corrective action until the offset is reset to zero.
The practical realization of this circuit is an integrator inserted between the deviation amplifier and the power stage. The
origin of the interchangeable terms "integral" control and (automatic) "reset" is evident.
How does a proportional-plus-integral controller behave in a cryogenic system?
First, in the idealized case, let us again assume an infinite thermal conductivity, which results in zero thermal resistance
between the sensor and the heater. The reset integrator continues to integrate until the error signal reaches zero, which
stops the integral action, but keeps its output at the level corresponding to that needed by the power stage to overcome
the droop. This output is now the only drive to the power stage since the proportional error signal has been forced to
zero. No overshoot will occur since zero thermal resistance eliminates the thermal lag which is the cause of overshoot.
The zero thermal time constant also means that any amount of reset will eventually force the system to zero error.
Before we switch the discussion back to real systems, let us deal with the nomenclature and units involved in integral
control. Automatic reset action can be expressed in terms of a time constant (minutes) or its inverse, reset rate (repeats
per minute). The reset time constant is the time required—measured in minutes—for the reset circuit to integrate to full
output with an input signal which is constant and equal to the proportional band error signal. The amount of reset action
can also be measured in "repeats per minute", or the number of times which the integrator can integrate between zero
and full output in a time period of one minute for the constant proportional band error signal. Thus, if the time constant
were, say, two minutes, this is the same as saying that the reset circuitry repeats the proportional action in two minutes,
or ½ repeats per minute.
The term "reset windup" refers to a condition occurring in reset controller when an offset persists for a sufficiently long
time. The integration of the error, with time, will cause the integrator to saturate or "windup" at maximum output and
remain so until the control point is traversed. By the time this has happened, a large overshoot may have occurred. This
problem can be prevented by disabling the reset action when controller response goes outside the proportional band. A
controller such as the DRC-82C accomplishes this with an anti-reset windup (or reset inhibit) circuit.
4
Application Notes
Lake Shore Cryotronics, Inc.
The Real World Revisited
Since a real cryogenic system has non-zero thermal resistance, the value of the reset is important in setup of the
controller. The amount of reset desired is dependent on: (1) the time required for the control sensor to reach equilibrium
once it enters the proportional band; and (2) the amount of output signal required from the reset action to overcome the
cooling power of the cryogenic system. For example, assume that 50% output is required and the time to reach
equilibrium is 3 seconds (.05 minutes). Therefore the repeats per minute is 10 and the time constant is 0.1 minutes. In
actuality, this is not easy to determine without a few tries. Almost always, however, the time constant increases with
increasing temperature so that if one is operating over a broad temperature range, finding the appropriate time constants
for the two extremes will bracket the appropriate time constants within that temperature range. Once the correct time
constant has been selected, the system should settle to its control set point within two or three time constants. If
significant overshoot is still occurring, the system design should be carefully reviewed.
V ADDING DERIVATIVE (RATE) TO THE TEMPERATURE CONTROL LOOP
If there is still an overshoot of the control temperature during transient changes of the set point within one's system, it can
be significantly reduced by the addition of a third control function to the controller, called rate or derivative control.
Normally, overshoot can be attributed to one of two causes: (1) the application of much more power than is required to
maintain the system at its desired set point; or (2) the result of the thermal response relationships between the cooling
power, the heating power, and the control sensor. The best solution to the first possibility is to reduce the available power
as discussed previously. The second problem normally occurs with a large thermal mass, where response is slow and
overshoot due to the thermal inertia of the system can be quite large. This overshoot is caused by the time lag between a
change in output power and the control sensor sensing this change. In very large non-cryogenic systems this time lag
can be 10-30 minutes. In cryogenic systems, it is usually less than a minute, even near room temperature. Consequently,
placement of the control sensor with respect to the heater is extremely important in the design of a cryogenic system, as
is the placement of both the heater and sensor with respect to the cooling power.
Rate action can be achieved by means of a differentiator circuit which
provides a signal proportional to the rate of temperature change, and
which is subtracted from the proportional output signal. This reduces
the effective overall amplifier gain driving the output power stage. The
reduced gain effectively increases the proportional band of the
controller. This slows down the rate of temperature rise and therefore
allows more time for the block to stabilize. Consequently, the
overshoot is substantially reduced or eliminated, depending on the
magnitude of the thermal problem, as is indicated in Figure 6.
The addition of rate is necessary only because of inherent thermal
problems which cannot be substantially eliminated by improvements
in thermal design. Also note that rate is effective only during the
transition from one set point to another. Near or at the set point, rate
has a destabilizing influence. It should therefore be normal practice to
turn off the rate control when near the control point.
FIGURE 6. The effect of adding Rate to the control
circuit to dynamically widen the proportional band and
reduce the overshoot which would occur in its absence.
The differentiator circuit should precede the reset integrator in the
circuit so that the deviation and derivative signals acting on the integrator input will be just sufficient to create the proper
reset value by the time the temperature reaches set point. In some cases, it is important for the rate circuit to precede the
deviation amplifier as well, i.e., immediately following the sensor input. This would then prevent the rate circuit from
operating on changes in the set point, such as in temperature seep applications. Fortunately, most sweeping is done
slowly enough so as to be unaffected by typical rate time constants.
To determine the rate control setting (in seconds) for a system, an abrupt increase in power is applied to the system
while in equilibrium. The time delay is then observed to the start of the resulting temperature increase as indicated by the
control sensor. This delay corresponds to the value to be set on the rate control.
Application Notes
5
Lake Shore Cryotronics, Inc.
VI SENSOR CONSIDERATIONS
Sensor Gain Revisited: Since a controller will amplify input noise as well as sensor signal, it becomes important to
consider sensor performance when designing a complete system. The Lake Shore DT-500 Series Sensors have a
voltage-temperature characteristic which lend themselves to cryogenic temperature control use because of their high
sensitivity at low temperatures (Figure 3). Coupled with this sensitivity is an extremely low noise-level which results, in
part, from assembly techniques used for all DT-500 Sensors which comply with the relevant portions of MIL STD 750C. It
is therefore possible to obtain short-term control at low temperatures which can approach 0.1 mK in specially designed
systems such as the Lake Shore calibration facility. Even above 30 K, where the sensitivity is reduced by a factor of 20,
short-term controllability is better than 2 mK.
With diodes, there is no need for a sensor pre-amplifier, which would precede the set point control and deviation
amplifier. However, in the case of resistance thermometers, including both semiconductor and metal types, a preamplifier becomes necessary. In a dc measurement system, such as is used in the DRC-82C, it is sometimes possible to
obtain temperature control stability with resistance thermometers superior to that obtainable with diodes. This requires a
highly stable and adjustable constant current source in addition to a pre-amplifier designed for very low noise and drift.
The choice of sensor is not at all obvious; it depends on many factors besides sensitivity, including sensor size, time
response, power dissipation, magnetic field dependence and temperature range. In the less common case of cryogenic
thermocouples, the very low sensitivity (10uV/K) requires quite large pre-amplifier gains and a stable reference junction
arrangement. Thermocouples are sometimes used when sensor size or time response are more important than
temperature stability and accuracy. At cryogenic temperatures, thermocouple accuracy does not approach that of a
semiconductor diode or resistance thermometer when either are properly installed.
VII ANALOG VERSUS DIGITAL CONTROL
In this day of computers, designing digital instrumentation with a microprocessor is definitely in vogue. In a digital control
system, the sensor voltage is digitized by an analog-to-digital (AD) converter. The digitized temperature is then compared
to the digital set point within the microprocessor and by means of an appropriate algorithm, the average power to the
heater is adjusted.
A converter with a 14 bit resolution (1 part in 16,384) enables the microprocessor to determine the temperature to
approximately 4 mK at 4.2 kelvin using the diode sensor of Figure 2. In a system which is inherently stable, the control
temperature stability can be no better than the temperature resolution of the AD converter (4 mK for this example). Costeffective AD converters with such resolution have sampling times in the half-second range. In the world of ovens,
furnaces, and other large industrial processes which operate above room temperature, stable control can be maintained
by digital systems updating temperature only once or twice a second. This is for the same reason that ON-OFF
controllers are successful in these cases: the large thermal time constants of the controlled environments.
However, as discussed in Section II, the time constants are much shorter in cryogenic systems, so much so that
temperature can, and frequently does, change at a rate which exceeds the sampling frequency of a typical digital
cryogenic controller (approximately 2 Hz). A good example is a mechanical refrigerator based on the Gifford-McMahon
cycle. At 10 kelvin and below, these refrigerators, unloaded, often have a peak-to-peak variation in temperature which
exceeds 1 kelvin at a nominal 3 Hz frequency. That variation represents an inherent disadvantage which is difficult for the
all-digital system to overcome since the sampling rate is lower than the frequency of the temperature variation. The
Sampling Theorem of Electrical Engineering implies that no sampled data control system can be stable unless it is
sampled at a rate which exceeds at least twice the highest frequency variation within the system.
Some designers of all-digital controllers for cryogenic temperatures appear to have overlooked this sampling rate
problem. There are also examples of digital controller which fail to achieve optimum performance because of the design
of their output stage: heater power is varied on a cyclical time-proportioning ON-OFF basis. This often introduces noise
within the system which may interfere with the cryogenic experiment.
An advantage that the microprocessor and its read-only memory provides for users of digital controllers is that of a direct
reading (in temperature) set point and sensor readout. However, as noted in Section III, this feature may exact a price. In
the real world, there is always an error due to lack of perfect conformity between the true sensor voltage- (or resistance-)
temperature characteristic and the value actually stored in memory. This error will depend on the degree of non-linearity
of the characteristic and on the amount of storage available. It is seldom cost-effective to keep the conformity error as
small as the useful resolution of the controller system. Thus, in the 14-bit system referred to earlier in this section, its 4
mK resolution would be swamped by, e.g., a conformity-limited 100 mK. Fortunately, in a controller such as the DRC82C, the user can select either a temperature or voltage (resistance) set point and readout.
The choice between analog and digital controllers turns out to be not a choice at all but an optimum combination of the
best features of each. True analog control provides a heater output that is a continuous function of the sensor signal, and
so eliminates the sampled data problem. This analog control may be combined with digital circuitry for readout of sensors
and power output, for setting the PID control parameters and for deriving the set point signal. This approach is used in
most of the Lake Shore Cryotronics, Inc. controllers.
6
Application Notes
Lake Shore Cryotronics, Inc.
For Further Reading
1.
E. M. Forgan, "On the Use of Temperature Controllers in Cryogenics". Cryogenics 14 (1974), pp. 207-214. This is a
cogent discussion of the interaction between the electrical and thermal response times in a typical cryogenic control
system. The mathematical analyses are straightforward and relatively easy to follow.
2.
A series on "process Control" published in the journal, Measurement & Control, Part 3, "On/Off and Proportional
Control", September 1984, pp. 165-170; Part 4, "Reset and Rate Control", October 1984, pp. 133-145; Part 5,
"Selecting the Mode of Control", December 1984, pp. 132-136. Some of this material has appeared in "Principles of
Temperature Control", available from Gulton Industries, West Division. Unlike reference 1, the discussion is not
related to cryogenics but temperature control system principles are briefly and clearly explained.
3.
C. L. Pomernacki, "Micro Computer-Based Controller for Temperature Programming the Direct Inlet Probe of a High
Resolution Mass Spectrometer", Review of Scientific Instruments, 48 (1977), pp. 1420-1427.
4.
W. M. Cash, E. E. Stansbury, C. F. Moore, and C. R. Brooks, "Application of a Digital Computer to Data Acquisition
and Shield Temperature Control of a High-Temperature Adiabatic Calorimeter", Review of Scientific Instruments, 52
(1981), pp. 895-901.
5.
R. B. Strem. B. K. Das, and S. C. Greer, "Digital Temperature Control and Measurement System", Review of
Scientific Instruments, 52 (1981), pp. 1705-1708.
Application Notes
7
Lake Shore Cryotronics, Inc.
Standard Curve 10
Standard Curve 10: Measurement Current = 10 µA ±0.05%
T (K)
Voltage
dV/dT
(mV/K)
T (K)
Voltage
dV/dT
(mV/K)
T (K)
Voltage
dV/dT
(mV/K)
1.40
1.60
1.80
2.00
2.20
1.69812
1.69521
1.69177
1.68786
1.68352
–13.1
–15.9
–18.4
–20.7
–22.7
16.0
16.5
17.0
17.5
18.0
1.28527
1.27607
1.26702
1.25810
1.24928
–18.6
–18.2
–18.0
–17.7
–17.6
95.0
100.0
110.0
120.0
130.0
0.98564
0.97550
0.95487
0.93383
0.91243
–2.02
–2.04
–2.08
–2.12
–2.16
2.40
2.60
2.80
3.00
3.20
1.67880
1.67376
1.66845
1.66292
1.65721
–24.4
–25.9
–27.1
–28.1
–29.0
18.5
19.0
19.5
20.0
21.0
1.24053
1.23184
1.22314
1.21440
1.19645
–17.4
–17.4
–17.4
–17.6
–18.5
140.0
150.0
160.0
170.0
180.0
0.89072
0.86873
0.84650
0.82404
0.80138
–2.19
–2.21
–2.24
–2.26
–2.28
3.40
3.60
3.80
4.00
4.20
1.65134
1.64529
1.63905
1.63263
1.62602
–29.8
–30.7
–31.6
–32.7
–33.6
22.0
23.0
24.0
25.0
26.0
1.17705
1.15558
1.13598
1.12463
1.11896
–20.6
–21.7
–15.9
–7.72
–4.34
190.0
200.0
210.0
220.0
230.0
0.77855
0.75554
0.73238
0.70908
0.68564
–2.29
–2.31
–2.32
–2.34
–2.35
4.40
4.60
4.80
5.00
5.50
1.61920
1.61220
1.60506
1.59782
1.57928
–34.6
–35.4
–36.0
–36.5
–37.6
27.0
28.0
29.0
30.0
32.0
1.11517
1.11212
1.10945
1.10702
1.10263
–3.34
–2.82
–2.53
–2.34
–2.08
240.0
250.0
260.0
270.0
280.0
0.66208
0.63841
0.61465
0.59080
0.56690
–2.36
–2.37
–2.38
–2.39
–2.39
6.00
6.50
7.00
7.50
8.00
1.56027
1.54097
1.52166
1.50272
1.48443
–38.4
–38.7
–38.4
–37.3
–35.8
34.0
36.0
38.0
40.0
42.0
1.09864
1.09490
1.09131
1.08781
1.08436
–1.92
–1.83
–1.77
–1.74
–1.72
290.0
300.0
310.0
320.0
330.0
0.54294
0.51892
0.49484
0.47069
0.44647
–2.40
–2.40
–2.41
–2.42
–2.42
8.50
9.00
9.50
10.0
10.5
1.46700
1.45048
1.43488
1.42013
1.40615
–34.0
–32.1
–30.3
–28.7
–27.2
44.0
46.0
48.0
50.0
52.0
1.08093
1.07748
1.07402
1.07053
1.06700
–1.72
–1.73
–1.74
–1.75
–1.77
340.0
350.0
360.0
370.0
380.0
0.42221
0.39783
0.37337
0.34881
0.32416
–2.43
–2.44
–2.45
–2.46
–2.47
11.0
11.5
12.0
12.5
13.0
1.39287
1.38021
1.36809
1.35647
1.34530
–25.9
–24.8
–23.7
–22.8
–21.9
54.0
56.0
58.0
60.0
65.0
1.06346
1.05988
1.05629
1.05267
1.04353
–1.78
–1.79
–1.80
–1.81
–1.84
390.0
400.0
410.0
420.0
430.0
0.29941
0.27456
0.24963
0.22463
0.19961
–2.48
–2.49
–2.50
–2.50
–2.50
13.5
14.0
14.5
15.0
15.5
1.33453
1.32412
1.31403
1.30422
1.29464
–21.2
–20.5
–19.9
–19.4
–18.9
70.0
75.0
80.0
85.0
90.0
1.03425
1.02482
1.01525
1.00552
0.99565
–1.87
–1.91
–1.93
–1.96
–1.99
440.0
450.0
460.0
470.0
475.0
0.17464
0.14985
0.12547
0.10191
0.09062
–2.49
–2.46
–2.41
–2.30
–2.22
Lighter numbers indicate truncated portion of Standard Curve 10 corresponding to the reduced temperature range of
DT-471 diode sensors. The 1.4 – 325 K portion of Curve 10 is applicable to the DT-450 miniature silicon diode sensor.
8
Application Notes
Lake Shore Cryotronics, Inc.
POLYNOMIAL REPRESENTATION
Curve 10 can be expressed by a polynomial equation based on the Chebychev polynomials. Four separate ranges are
required to accurately describe the curve. Table 1 lists the parameters for these ranges. The polynomials represent
Curve 10 on the preceding page with RMS deviations of 10 mK. The Chebychev equation is:
n
T (x ) = ∑ ai ti (x )
(1)
i =0
where T(x) = temperature in kelvin, ti(x) = a Chebychev polynomial, and ai = the Chebychev coefficient. The parameter x is
x=
a normalized variable given by:
(V − VL ) − (VU − V )
(VU − VL )
(2)
where V = voltage and VL & VU = lower and upper limit of the voltage over the fit range. The Chebychev polynomials can
ti +1 (x ) = 2 xti (x ) − ti −1 (x )
be generated from the recursion relation:
Alternately, these polynomials are given by:
t0 (x ) = 1, t1 (x ) = x
(3)
ti (x ) = cos i × arccos (x )
(4)
The use of Chebychev polynomials is no more complicated than the use of the regular power series and they offer
significant advantages in the actual fitting process. The first step is to transform the measured voltage into the normalized
variable using Equation 2. Equation 1 is then used in combination with equations 3 and 4 to calculate the temperature.
Programs 1 and 2 provide sample BASIC subroutines which will take the voltage and return the temperature T calculated
from Chebychev fits. The subroutines assume the values VL and VU have been input along with the degree of the fit. The
Chebychev coefficients are also assumed to be in any array A(0), A(1),..., A(idegree).
An interesting property of the Chebychev fits is evident in the form of the Chebychev polynomial given in Equation 4. No
term in Equation 1 will be greater than the absolute value of the coefficient. This property makes it easy to determine the
contribution of each term to the temperature calculation and where to truncate the series if full accuracy is not required.
FUNCTION Chebychev (Z as double)as double
REM Evaluation of Chebychev series
X=((Z-ZL)-(ZU-Z))/(ZU-ZL)
Tc(0)=1
Tc(1)=X
T=A(0)+A(1)*X
FOR I=2 to Ubound(A())
Tc(I)=2*X*Tc(I-1)-Tc(I-2)
T=T+A(I)*Tc(I)
NEXT I
Chebychev=T
END FUNCTION
FUNCTION Chebychev (Z as double)as double
REM Evaluation of Chebychev series
X=((Z-ZL)-(ZU-Z))/(ZU-ZL)
T=0
FOR I=0 to Ubound(A())
T=T+A(I)*COS(I*ARCCOS(X))
NEXT I
Chebychev=T
END FUNCTION
Program 1. BASIC subroutine for evaluating the
temperature T from the Chebychev series using
Equations (1) and (3). An array Tc (idegree) should be
dimensioned. See text for details.
Program 2. BASIC subroutine for evaluating the
temperature T from the Chebychev series using
Equations (1) and (4). Double precision calculations are
recommended.
==
NOTE: arccos ( X ) =
 X 
π
− arctan 

2
2
 1− X 
Table 1. Chebychev Fit Coefficients
2.0 K to 12.0 K
VL = 1.32412
VU = 1.69812
A(0) = 7.556358
A(1) = -5.917261
A(2) = 0.237238
A(3) = -0.334636
A(4) = -0.058642
A(5) = -0.019929
A(6) = -0.020715
A(7) = -0.014814
A(8) = -0.008789
A(9) = -0.008554
A(10) = 0.039255
Application Notes
12.0 K to 24.5 K
VL = 1.32412
VU = 1.69812
A(0) = 17.304227
A(1) = -7.894688
A(2) = 0.453442
A(3) = 0.002243
A(4) = 0.158036
A(5) = -0.193093
A(6) = 0.155717
A(7) = -0.085185
A(8) = 0.078550
A(9) = -0.018312
A(10) = -0.116823
24.5 K to 100.0 K
VL = 1.32412
VU = 1.69812
A(0) = 71.818025
A(1) = -53.799888
A(2) = 1.669931
A(3) = 2.314228
A(4) = 1.566635
A(5) = 0.723026
A(6) = -0.149503
A(7) = 0.046876
A(8) = -0.388555
A(9) = 0.056889
A(10) = 0.015619
A(11) = 0.058580
100 K to 475 K
VL = 1.32412
VU = 1.69812
A(0) = 287.756797
A(1) = -194.144823
A(2) = -3.837903
A(3) = -1.318325
A(4) = -0.109120
A(5) = -0.393265
A(6) = 0.146911
A(7) = -0.111192
A(8) = 0.028877
A(9) = -0.029286
9
Lake Shore Cryotronics, Inc.
DT-470 SERIES TEMPERATURE SENSORS INSTALLATION AND OPERATION
There are three aspects of using a temperature sensor which are critical to its optimum performance. The first involves
the proper electrical and thermal installation of the connecting leads which run to the sensor, while the second aspect is
the actual mounting of the sensor to the sample assembly. The final concern is the measurement electronics used for
reading and recording temperature data from the sensor.
CONNECTING LEADS
Although the majority of the DT-470 series sensors are two lead devices, measurements should preferably be made
using a four wire configuration to avoid all uncertainties associated with the lead resistance. This is done by using four
connecting leads to the device and connecting the V+ and I+ leads to the anode and the V- and I- leads to the cathode
as shown in Figure 1. The exact point at which the connecting leads are soldered to the device leads results in negligible
temperature measurement uncertainties.
In a two wire measurement configuration, the voltage connections (point A in Figure 1) are made near or at the current
source so only two leads are actually connected to the device. Some loss in accuracy can be expected since the voltage
measured at the voltmeter is the sum of the diode voltage and the voltage drop across the connecting leads. The exact
temperature uncertainty will depend on the temperature range and lead resistance. For a 10 ohm lead resistance, the
diode voltage will be offset by 0.1 mV which gives a negligible temperature error at liquid helium temperature but a 50mK
error near liquid nitrogen temperature. Note the DI and CY adapter can be used only in a two wire configuration.
An excessive heat flow through the connecting leads to any temperature sensor can create a situation where the active
sensing element (for the DT-470 this is the diode chip) is at a different temperature than the sample to which the sensor
is mounted. This is then reflected as a real temperature offset between what is measured and the true sample
temperature. Such temperature errors can be eliminated by proper selection and installation of the connecting leads.
In order to minimize any heat flow through the leads, the leads should be of small diameter and low thermal conductivity.
Phosphor-bronze or manganin wire is commonly used in sizes 32 or 36 AWG. These wires have a fairly poor thermal
conductivity yet the resistivities are not so large as to create any problems in four wire measurements.
Lead wires should also be thermally anchored at several temperatures between room temperature and cryogenic
temperatures to guarantee that heat is not being conducted through the leads to the sensor. A final thermal anchor at the
sample itself is a good practice to assure thermal equilibrium between the sample and temperature sensor. Note that the
CU, CY, BO, and DI mounting adapters serve as their own sample thermal anchor.
If the connecting leads have only a thin insulation such as Formvar or other varnish type coating, a simple thermal
anchor cn be made by winding the wires around a copper post or other thermal mass and bonding them in place with a
thin layer of GE 7031 varnish. There are a variety of other ways in which thermal anchors can be fabricated and a
number of guidelines which may be found in detail in the references given below.
SENSOR MOUNTING
General Comments
Before installing the DT-470 sensor, identify which lead is the anode and which lead is the cathode by referring to the
accompanying device drawings. Be sure that the lead identification remains clear even after installation of the sensor,
and record the serial number and location.
The procedure used to solder the connecting leads to the sensor leads is not very critical and there is very little danger in
overheating the sensor, If for some reason the leads have to be cut short, they should be heat sunk with a copper clip or
needle-nose pliers before soldering. Standard rosin core electronic solder (m.p. - 180 C) is suitable for most applications.
Applications involving the use of the SD package up to 200° C will require a higher melting point solder. A 90% Pb 10%
Sn solder has been used quite successfully with a rosin flux.
For all adapters except the CY, CU, and DI, the leads are a gold-plated Kovar. Prolonged soldering times may cause the
solder to creep up the gold plated leads as the solder and gold alloy. This is not detrimental to the device performance.
When installing the sensor, make sure there are no shorts or leakage resistance between the leads or between the leads
and ground. GE-7031 varnish or epoxy may soften varnish-type insulations so that high resistance shunts appear
between wires if sufficient time for curing is not allowed. Teflon spaghetti tubing is useful for sliding over bare leads when
the possibility of shorting exists. Also, avoid putting stress on the device leads and allow for the contractions that occur
during cooling which could fracture a solder joint or lead if installed under tension at room temperature.
The DT-470 sensor is designed for easy removal for recalibration checks or replacement and the following discussions
for each of the adapters are geared in this direction. If semi-permanent mountings are desired, the use of Stycast epoxy
can replace the use of Apieson N Grease. In all cases, the mounting of the sensor should be periodically inspected to
verify that good thermal contact to the mounting surface is maintained.
10
Application Notes
Lake Shore Cryotronics, Inc.
DT-470-SD
The SD version is the basic package for the DT-470 sensor line from which all
other configurations are made using the appropriate adapter. The base of the
device has a gold metallized surface and is the largest flat surface on the
sensor. The base is electrically isolated from the sensing element and leads,
and all thermal contact to the sensor must be made through the base. A thin
braze joint around the sides of the SD package is electrically connected to the
sensing element. Contact to the sides with any electrically conductive material
must be avoided. When viewed with the base down and with leads towards the
observer, the positive lead (anode) is on the right.
For a removable mount, the Sd sensor can be3 held against the mounting surface with the CO adapter (see below) or
similar clamping mechanism. Any method of clamping the sensor must avoid excessive pressure and should be
designed so that thermal contractions or expansions do not loosen contact with the sensor. For uses restricted to below
325 K, a thin layer of Apiezon N Grease should be used between the sensor and sample to enhance the thermal contact.
The SD package can also be bonded with an epoxy such as Stycast. The sensor should be pressed firmly against the
surface during curing to assure a thin epoxy layer and good thermal contact. The device may be removed in the future by
using the appropriate epoxy stripper.
The SD adpater can be soldered using a rosin flux (non-corrosive) if extreme care is exercised. First, tin the base of the
sensor using a low wattage, temperature controlled soldering iron which will not exceed 200° C. Use only a minimal
amount of solder. Tin the surface to which the sensor is to bonded and again avoid an excessive thickness of solder.
Clean both the sensor and mounting surface of any residual flux. Next, re-heat the mounting surface to the melting point
of the solder, press the device into position and allow the sensor to warm to the melting point of the solder. After both
tinned surfaces have flowed together, remove the heat source and let the sample and sensor cool. Under no
circumstance should the sensor be heated above 200° C and the solder must be limited to only the base of the sensor.
Excess solder running up the sides of the SD package can create shorts. Repeated mounting and demounting of a
soldered sensor may eventually cause wetting deterioration and ruin the thermal contact to the sensing element,
although the nickel buffer layer should minimize these problems.
CAUTION: The preferred method for mounting the SD sensor is either the CO adapter or bonding with epoxy.
Lake Shore Cryotronics, Inc. will not warranty replace any device damaged by a user-designed clamp or
damaged through solder mounting.
DT-470-LR
The gold-plated copper LR adapter is designed for insertion into a 1/8 inch diameter
hole. A thin layer of Apiezon N Grease should be applied to the copper adapter
before insertion. This eases installation at room temperature and enhances the
thermal contact.
DT-470-CU / DT-470-DI / DT-470-CY
The gold-plated copper CU, DI, and CY
adapters serve as both sensor and thermal
anchor assembly. These adapters mount to a
flat surface with a 4-40 brass screw. Avoid
over-tightening the screw; use only enough
force to firmly hold the sensor in place. A
brass screw is recommended as the
differential thermal contraction between the
adapter and the screw causes the mounting
assembly to tighten as opposed to loosen
when the system cools. Apply a thin layer of
Apiezon N Grease to enhance thermal contact
between the adapter and mounting surface.
DT-470-CU / DT-470-DI
DT-470-CY
The CU adapter has four color-coded leads: Red (I-), Green (V-), Clear (V+), and Blue )I+). The CY adapter has two
color-coded leads: Yellow (+) and Green (-). The green lead on the DI adapter is the cathode.
Application Notes
11
Lake Shore Cryotronics, Inc.
DT-470-ET / DT-470-MT
DT-470-ET
DT-470-MT
Both adapters are gold-plated copper hex head bolts with the SD package mounted in a slot on the adapter head. The
ET adapter screws into a ¼ inch deep, 6-32 threaded hole while the MT adapter screws into a 6 mm deep, 3x0.5 mm
threaded hole. Before assembly the threads should be lightly greased with Apiezon N Grease Do not over-tighten since
the threads are copper and can be easily sheared. Finger tight should be sufficient.
DT-470-BO
The BO adapter should be mounted in the same manner as the CU. The BO adapter
contains its own thermal anchor and is an epoxy free assembly.
DT-470-CO
The CO adapter is a spring-loaded clamp to attach the DT-470-SD package to a flat
surface. It maintains pressure on the SD package as the temperature varies. First,
remove the hold down cap which holds the three piece CO assembly together. The CO
assembly should appear as shown in the accompanying drawings. Bolt the assembly
into a 4-40 threaded hole. The stop on the brass screw should rest against the
mounting surface and it also prevents over-compressing the spring. Lift the edge of the
clip using a small pliers or screw driver. Slide the SD package into place underneath
the clip and gently lower the clip onto the lid of the SD package. Note that a slot is cut
underneath the clip to accept the SD package. Refer to the drawing for details. If the
device is to be used only below 325 K, apply a layer of Apiezon N Grease between the
SD package and mounting surface to enhance thermal contact.
12
Application Notes
Lake Shore Cryotronics, Inc.
FIGURE 1. Four-Wire Configuration for DT-470 Installation
SENSOR OPERATION
Temperature controllers and thermometer instrumentation manufactured by Lake Shore Cryotronics are designed to be
directly compatible with the DT-470 sensor to give optimum performance and accuracy together with direct temperature
readouts. Simply follow the instructions provided with the instrument concerning sensor connection and instrument
operation. If a user-supplied current source, voltmeter, or other instrumentation are going to used with the DT-470
sensor, special attention should be given to the following details.
The DT-470 is designed to operate at a constant current of 10 microamperes while the voltage variation with temperature
is monitored. Therefore, the accuracy of the temperature measurement depends directly onf the specifications of the
current source and the voltmeter. A current source operating at the level of 10 ±0.01 microamperes (±0.1%) gives a
nominal temperature uncertainty of 10 millikelvin (0.01 K) which is probably suitable for most applications The voltmeter
resolution required can be estimated from the sensitivity (dV/Dt) of the DT-470:
Temperature (K)
305
77
4.2
Sensitivity (mV/K)
2.4
1.9
33
Multiplying the above sensitivity by the desired temperature resolution in kelvin will give the required voltage resolution in
millivolts.
The static impedance of the DT-470 sensor operating at a 10 microampere current is on the order of 100,000ohms.
Therefore, the input impedance of the voltmeter must be significantly larger than this to avoid measurement errors.
Voltmeters with input impedances of greater than 109 or 1010 ohms should be used.
Good quality instrumentation must be used and all instrumentation and wiring should be properly grounded and shielded.
Temperature measurement errors will result if there is excessive AC noise or ripple in the circuitry. Further details can be
found in the article by Krause and Dodrill given in the references.
NOTE: All materials mentioned which are used in sensor installation are available from Lake Shore Cryotronics, Inc.
References
Krause, J. K. and Swinehart, P. R. (1985). Demystifying Cryogenic Temperature Sensors. Photonics Spectra. August, 6168. (Available on request from Lake Shore Cryotronics, Inc.
Krause, J. K. and Dodrill, B. C. (1986). Measurement System Induced Errors in Diode Thermometry. Review of Scientific
Instruments 57 (4), 661-665. (Available on request from Lake Shore Cryotronics, Inc.)
Sparks, L. L. (1983). Temperature, Strain, and Magnetic Field Measurements. In Materials at Low Temperatures, Ed. By
R. P. Reed and A. F. Clark. American Society of Metals, Metals Park, 515-571.
White G. K. (1979). Experimental Techniques in Low Temperature Physics. Clarendon Press, Oxford.
Application Notes
13
Lake Shore Cryotronics, Inc.
MEASUREMENT SYSTEM INDUCED ERRORS IN DIODE THERMOMETRY
by John K. Krause and Brad C. Dodrill
Diode temperature sensors are capable of being used at the accuracy level of a few hundredths of a kelvin. However, in
order to achieve this performance, proper measurement techniques must be used. Poorly shielded or improperly
grounded measurement systems can introduce ac noise which will create an apparent shift in the dc voltage reading
across a diode sensor. This results in a temperature measurement error which may approach several tenths of a kelvin.
The presence of the ac noise in question is not obvious during normal usage and several quick tests are outlined to verify
whether or not a noise problem exists. Experimental data and derivations from theoretical p-n junction characteristics are
given which correlate the ac noise level with possible voltage/temperature measurement errors. These results can be
used in estimating the accuracy and performance of a temperature measurement system. Several of the more common
problems which introduce noise into diode circuitry are described.
INTRODUCTION
Current technological uses of temperature sensors require better calibration accuracies and better device performance
than ever before. However, the assurance of an accurate temperature measurement does not stop with simply the
sensor specifications. Just as critical is the instrumentation used with the sensor and the manner in which the
instrumentation is used. This paper concentrates on identifying, verifying, and eliminating an often overlooked
instrumentation or system-induced error in the use of diode temperature sensors.
I. PROBLEM DEFINITION
Semiconductor diode temperature sensors have been in use for over
20 years and, with the advantages they offer over resistance sensors
or thermocouples for many applications, their popularity continues to
increase. Diodes are operated at a constant current, typically 1, 10, or
100 µA, while the voltage variation with temperature (V[T]) is
monitored. The diode sensor has a useful temperature range from
above room temperature to as low as 1 K, with reproducibilities to
better than ±50 mK. Figure 1 shows the voltage variation with
temperature for a typical silicon diode temperature sensor.
An error arises in diode thermometry if the excitation current is not a
true dc current but has an ac component superimposed on the dc.
Although the ac component can be due to a poorly designed current
supply, a more common source of the ac is noise induced in the
measurement circuit. This noise can be introduced through improper
shielding, improper electrical grounds, or ground loops. Currently
available voltmeters have sufficient normal-mode rejection
capabilities in their dc measurement modes that these noise effects
can go completely unnoticed if they are not explicitly checked. The
equivalent temperature error which may be caused by this problem is
typically a few tenths of a kelvin, although an extreme case with a 4 K
error has been observed.
The effect of the ac noise appears as a shift in the dc voltage
measurement due to the nonlinear current/voltage characteristics of
the diode. An illustration of this effect is shown in Fig. 2 where an
exaggerated IV curve is given. An induced ac noise current
superimposed on the dc operating current (Idc) is shown along the
current axis. The resulting voltage seen by the voltmeter is shown
along the voltage axis. The nonlinear IV characteristics of the diode
have caused a distortion in the ac voltage signal making it
asymmetrical with respect to the voltage reading corresponding to Idc.
When a voltmeter operating in a dc voltage mode reads this signal,
the signal is processed (by integrating, filtering, etc.) to give an
average dc voltage reading which will be lower than expected. The
apparent temperature measurement will then be too high. Note that
this voltage offset is due to induced currents in the total measuring
system and is not simply a voltage pickup by the diode itself. An ac
voltage superimposed symmetrically about the dc operating voltage
of the diode would not cause a dc voltage offset.
14
FIGURE 1. Voltage-temperature curve for a typical
silicon diode temperature sensor at a constant current
of 10 µA.
FIGURE 2. IV curve for a silicon diode sensor showing
effect of an induced ac current superimposed on the dc
operating current Idc. The expected dc operating
voltage is Vdc, which is shifted from the average voltage
Vave indicated by the voltmeter in a dc measurement
mode.
Application Notes
Lake Shore Cryotronics, Inc.
There are two simple techniques which can be used to test whether these errors might be present in a measuring
system. The first is to connect a capacitor (about 10 µF) in parallel with the diode to act as a shunt for any ac noise
currents. The capacitor must have low leakage current so as not to alter the dc current through the diode. The capacitor
may also alter the time response of the measurement system, so allow sufficient time for the capacitor to charge and for
the system to equilibrate. If the dc voltage reading across the diode increases with the addition of the capacitor, there are
probably ac noise currents present. The second method simply involves measuring the ac voltage signal across the
diode. Although an oscilloscope is often the logical choice for looking at ac signals, many do not have the sensitivity
required and they often introduce unwanted grounds into the system and compound the problem. Most testing can be
performed with the same digital voltmeter used to measure the dc voltage by simply selecting the ac voltage function.
There should be no ac voltage across the diode. If there is, the data presented in the following sections can be used to
estimate the potential error in the temperature measurement.
II. EXPERIMENTAL
In order to quantify the effects of induced currents on silicon diode
temperature sensors, the circuit of Fig. 3 was used to superimpose an
ac current on the dc operating current. The dc current source was
battery powered with currents selectable from < 1 µA to > 1 mA.. The
signal generator could be varied in both amplitude and frequency. All
voltage measurements were made with a Hewlett-Packard 3456A
voltmeter in either the dc voltage mode or the ac (rms) voltage mode.
The dc measurements were taken with an integration time of 10
power line cycles without using the filtering options available on the
voltmeter. The average of several readings was taken to reduce the
measurement uncertainty. An oscilloscope was also used to doublecheck and monitor signal frequency, shape, and distortion, but the
oscilloscope was removed from the circuit when actual data were
recorded.
FIGURE 3. Measurement circuit schematic diagram.
Data were recorded at the three dc current values of 1, 10, and 100 µA with the temperature stabilized at 305, 77, or 4.2
K. At each temperature and dc current value, the dc voltage and the ac voltage across the diode were recorded as the
amplitude and frequency of the signal generator were varied. The dc voltage reading across the 10 kΩ standard resistor
was also monitored to verify that the dc component of the current remained constant to within 0.05%. In addition, the IV
characteristic of the diode was measured at each temperature from 0.1 to 150 µA.
Although detailed measurements were taken on only one diode, other diodes were randomly selected and spot checked
at all three temperatures and frequencies to verify consistency with the measured data. The diodes tested were of the
DT-500 series of Lake Shore Cryotronics, Inc. and have been in production long enough to have a substantial reliability
and calibration history.
III. RESULTS AND DISCUSSION
The data were analyzed by calculating a voltage offset ∆V. This offset is defined as the difference between the dc voltage
reading across the diode when operated with an ac + dc current and the dc voltage reading when operated with a pure dc
current (see Fig. 2). At first glance, the logical choice seems to be to examine the variation of this offset as a function of
the ac current amplitude. However, the ac (rms) voltage across the diode was chosen instead for two reasons, the first of
which is purely practical. In many circumstances, the ac voltage measurement can be made without any modifications to
existing measurement systems, so laboratory checks can be quickly taken and compared directly to the data presented
here to give an estimate of potential temperature errors. Second, in the calculations using the model presented below,
one unknown parameter could be eliminated from the calculations by using the voltage across the diode instead of the
current.
Figures 4 and 5 give the offset voltage as a function of the ac (rms) voltage across the diode for dc currents of 1, 10, and
100 µA with the ac current modulation at 60 Hz. The equivalent temperature error corresponding to the dc offset voltage
is indicated along the right edge of the figure. Figures 6 and 7 give similar plots but at a fixed 10 µA dc current with the ac
current modulation at 60, 1000, and 20,000 Hz. The magnitude of the dc offset voltages is consistent with what has been
observed in measurement systems when corrective action has been taken to eliminate noise problems. Special note
should be taken of the dc current independence in Fig. 4 and the frequency independence in Figs. 6 and 7. The data
taken at 305 K have not been shown as the results are qualitatively very similar to the 77 K measurements and can be
adequately described by the mathematical model which is presented below.
One surprising aspect of the data acquisition was how well the signal processing in the voltmeter could hide even high ac
levels in the dc measurement modes. For example, operating at 10 µA dc and 77 K with a rms noise level of 6 mV gives
a dc voltage offset of about 1.5 mV, which is about a 0.6 K temperature error. When reading the voltage signal using the
filtering and integrating capabilities of the HP 3456A, the dc voltage reading is stable to better than ±0.02 mV (8 mK).
Application Notes
15
Lake Shore Cryotronics, Inc.
This stability gives a deceptive view of exactly how accurate the
temperature measurement really is and emphasizes the importance of
checking all aspects of a measuring system.
The measured offset voltages shown in Figs. 4 and 6 can be
understood by using the well-known result from p-n junction theory:
I = Is [exp(eV / nkT) - 1]
(1)
where I = the forward current through the junction, Is = the reverse
saturation current, e = the electron charge, V = the voltage across the
junction, k = Boltzmann's constant, and T = the absolute temperature. n
is a parameter depending on the location of the generation and
recombination of the electrons and holes and typically has a value
between 1 and 2. This expression for the IV characteristics of a p-n
junction is valid from approximately 40 K to above 300 K for the silicon
diodes discussed here. Below 40 K, a new conduction mechanism
becomes dominant, suggesting the influence of impurity conduction,
carrier freezeout, increased ohmic behavior of the bulk material, and p1-6
i-n diode type behavior.
The only adjustable parameter in Eq. 1 which is necessary for the
present analysis is the parameter n. This parameter can be determined
quite easily from the IV characteristics of the silicon diode temperature
sensor. The parameter Is is eliminated by normalizing the IV curve to an
arbitrarily chosen point on the curve. The value of n = 1.8 was found to
give a relatively good fit to the IV data for both 305 and 77 K and has
been assumed in the present discussion.7 Equation (1) can now be
solved for V(I):
V(I) = (nkT / e)ln(I / Is + 1)
(2)
Substituting a dc current with an ac modulation, Idc + Iac cosωt, the
average voltage read by the voltmeter in the dc voltage mode can be
calculated from:
V =
z
1 T
V (I dc + I ac cos ωt )dt
T 0
FIGURE 4. DC offset voltage as a function of rms
ac voltage across a silicon diode temperature
sensor operating at 77 K. The symbols represent
data recorded at three different dc operating
currents with a 60 Hz signal superimposed. The
solid curve gives small signal model results while
the dashed curve represents the extended
calculations. Equivalent temperature errors are
indicated along the right edge.
(3)
where T = the period of integration of the voltmeter or approximately
2π/ω. Implied in this derivation is the assumption that ω is sufficiently
small so that effects from diode capacitance (on the order of picofarads)
can be ignored.
On carrying out the integration of Eq. (3) and subtracting V(Idc), the dc
offset voltage is:
∆V = V − V (I dc ) =
LM
MN
F
GG
H
FG
H
nkT
1
eVrms
1+ 1− 2
ln
e
2
nkT
IJ
K
2
I OP
JJ P
KQ
(4)
where Iac ≤ Idc + Is. If a small signal (linear) model is used, the rms
voltage across the diode can be easily related to Iac:
Vrms =
FG IJ
H K
I ac dV
2 dI
I =I dc
=
FG
H
1 nkT
2 e
IJ FG I IJ
KHI + I K
ac
dc
(5)
s
Evaluation of Eq. (5) and substitution back into (4) yields:
∆V =
LM
MN
F
GG
H
FG
H
nkT
1
eVrms
ln
1+ 1− 2
e
2
nkT
IJ
K
2
I OP
JJ P
KQ
(6)
2
where 2(eVrms / nkT) ≤ 1 for a physical solution. Equation (6) predicts
an offset voltage which is independent of both frequency and dc
operating current and is shown plotted in Fig. 4 by the solid line. The
agreement with the experimental measurements is quite good, verifying
the overall picture as to the effect of induced currents on diode
temperature sensors. The results recorded at 305 K are described
equally well by Eq. (6).
16
FIGURE 5. DC offset voltage as a function of rms ac
voltage across a silicon diode temperature sensor
operating at 4.2 K. The symbols represent data
recorded at three different dc operating currents with
a 60 Hz signal superimposed. Equivalent
temperature errors are indicated along the right
edge.
Application Notes
Lake Shore Cryotronics, Inc.
The utilization of the small signal model has the advantage of being
analytically simple. However, the model does not contain the nonlinearity
inherent in the forward biased IV characteristics of a p-n junction. In an
attempt to retain the non linear characteristics, V(Idc + Iac cosωt) was
expanded in a Fourier series. The first term (constant term) is just the average
dc voltage in Eq. (3) and is not seen by the voltmeter operating in an ac
measurement mode. The remaining terms in the Fourier series can then be
used to calculate the rms voltage which will be read by the voltmeter:
2
Vrms
1
=
T
z
T
0
LM
MN
∞
an cos nωt +
n =1
O
sin mωt P dt
PQ
2
∞
bm
m =1
(7)
where an and bm are the Fourier coefficients. In order to evaluate the Fourier
coefficients, V(I) was expanded in a power series around Idc. Sufficient terms
were maintained in both the power series expansion and in Eq. (7) to give a
second-order correction to Eq. (5):
Vrms
FG
H
1 nkT
=
2 e
IJ FG I
KH I + I
ac
dc
s
I FG1+ 5
JK GH 16 bI
I
J
+ I g JK
2
I ac
dc
2
1/ 2
(8)
s
Substitution of this result into Eq. (4) gives the 77 K offset voltages shown in
Fig. 4 by the dashed line. Slightly better agreement with the experimental data
is seen at the higher rms voltages. At 305 K, the two calculation methods are
in even better agreement and a plot similar to Fig. 4 would show no
difference. The details of the extended calculation have not been given as the
mathematics is somewhat tedious, and the slight discrepancies between the
small signal model and the extended model do not justify the added
complexity. For all practical purposes, Eq. (6) can be reliably used above 40
K.
FIGURE 6. DC offset voltage as a function of
rms ac voltage across a silicon diode
temperature sensor operating at 77 K. The
symbols represent data recorded at a 10 µA
dc current with the ac current modulation at
60, 1000, and 20,000 Hz.
The physics of a p-n junction at 4.2 K is not clearly understood and attempts
to correlate the present data by modeling low-temperature IV characteristic of
a diode failed. If the diode does take on a p-i-n type behavior, the different
curves shown in Fig. 5 for 1, 10, and 100 µA can possibly be understood in
terms of the additional current-dependent terms in the IV curve.6 Another
explanation for the significant offset voltage at 100 µA could be self-heating in
the diode. If the diode is operated at too high a power level, the diode has a
tendency to warm slightly above the surrounding environment. This will have
the effect of distorting the IV curve in the direction of lower voltages at higher
currents. This distortion will then increase the offset voltage. At 4.2 K, selfHeating usually becomes a problem as the current approaches 100 µA.
FIGURE 7. DC offset voltage as a function of
rms ac voltage across a silicon diode
temperature sensor operating at 77 K. The
symbols represent data recorded at a 10 µA
dc current with the ac current modulation at
60, 1000, and 20,000 Hz.
Application Notes
17
Lake Shore Cryotronics, Inc.
IV. CONCLUDING REMARKS
Noise in any measurement circuit is undesirable and should be eliminated to as great an extent as possible. The first
8
step is to electrically shield all instrumentation and wiring and use proper grounding techniques. Secondly, the diode
measurement circuit should have a single circuit ground which is generally made at the voltmeter and which then
requires a floating current source. The installation of the diode and its connecting leads should be done carefully to avoid
introducing any unwanted circuit ground connections such as an electrical short to a cryostat.
As a last resort, a "quick fix" can be used to eliminate much of the dc offset voltage with some degradation in the diode
circuit performance. A good quality capacitor (low leakage) can be placed across the diode to shunt the induced ac
currents similar to the test procedure used for identifying a noise problem. This is most easily done by connecting the
capacitor across the input to the voltmeter. The size of the capacitor needed will depend on the frequency of the noise
(generally related to the power line frequency of 60 Hz) and the dynamic impedance of the diode (on the order of a few
thousand ohms at a 10 µA operating current). A capacitor in the range of 10 to 20 µF should reduce most noise effects to
an acceptable level. However, because the capacitor increases the time constant in the circuit, a sluggish response
should be expected. In switching operations, 30 seconds or more may be required for the circuit to stabilize. This "quick
fix" is not meant as a substitute for proper measurement techniques, but in certain circumstances it may be useful.
Note added in proof. The capacitance values given above are for the elimination of the effects of low-frequency noise
such as 60 Hz. If high-frequency noise is a problem, an additional capacitor of lower capacitance value may be needed.
The reason for this is because larger capacitors often have an associated inductance which limits their usefulness as a
high-frequency shunt.
1
A. S. Grove, Physics and Technology of Semiconductor Devices (Wiley, New York, 1967), Chap. 6.
2
S. M. Sze, Physics of Semiconductor Devices (Wiley Interscience, New York, 1969), Chap. 4.
3
D. A. Fraser, The Physics of Semiconductor Devices (Clarendon, Oxford, 1983).
4
R. V. Aldridge, Solid-State Electron. 17, 617 (1974).
5
V. Chopra and G. Dharmadurai, Cryogenics 20, 659 (1980).
6
D. A. Kleinman, Bell Syst. Tech. J. 35, 685 (1956).
7
P. R. Swinehart, L. A. Smith, and J. K. Krause (private communication); values are consistent with numerous other
measurements made at Lake Shore Cryotronics, Inc.
8
R. Morrison, Grounding and Shielding Techniques in Instrumentation (Wiley, New york, 1977), Vol. 2.
18
Application Notes